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Deprecated: strlen(): Passing null to parameter #1 ($string) of type string is deprecated in /afs/ist.utl.pt/groups/mysolutions/web/wiki/includes/libs/rdbms/database/Database.php on line 578 http://www.mysolutions.tecnico.ulisboa.pt//mysolutions/wiki/api.php?action=feedcontributions&feedformat=atom&user=Ist23437My Solutions - Contribuições do utilizador [pt]2025-11-01T04:34:12ZContribuições do utilizadorMediaWiki 1.35.2 Deprecated: strlen(): Passing null to parameter #1 ($string) of type string is deprecated in /afs/ist.utl.pt/groups/mysolutions/web/wiki/includes/libs/rdbms/database/Database.php on line 578
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Deprecated: strlen(): Passing null to parameter #1 ($string) of type string is deprecated in /afs/ist.utl.pt/groups/mysolutions/web/wiki/includes/libs/rdbms/database/Database.php on line 578 http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6084Laser Safety Manual2025-03-20T17:42:20Z<p>Ist23437: /* Electrical hazards, including high voltage */</p>
<hr />
<div>'''Latest revision: March 2025'''<br />
<br />
Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should be laid in areas prone to water accumulation (e.g., near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
! Laser class !! Description !! Safety measures<br />
|-<br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
|| No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
|| Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
|| Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
|| Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
|rowspan="3"| '''Class 3''' ||colspan="2"| May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
|-<br />
|'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers. || Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
|-<br />
|'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers. || Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
|| Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also the section [[http://www.mysolutions.tecnico.ulisboa.pt/wiki/index.php?title=Laser_Safety_Manual#L2I_floor_plan|L2I floor plan]] below for information about the location of each item.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE.<br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. The tables below detail the layout of each one, with the differential switches highlighted in blue.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board1.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
|bgcolor = "0088FF" | 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
|bgcolor = "0088FF" | 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 2'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board2.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=7 | Top<br />
| 1 || 40 || Differential switch for single phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets (Fastlite)<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| rowspan=3 | Middle<br />
| 8 || 40 || Differential switch for three-phase sockets<br />
|-<br />
| 9 || 16 || Three-phase socket B<br />
|-<br />
| 10 || 40 || Three-phase socket C<br />
|-<br />
| Bottom || 11 || 63 || Global panel circuit breaker<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 3'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board3.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=14 | Top<br />
| 1 || 16 || Single-phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| 8 || 16 || Single-phase sockets<br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || || <br />
|-<br />
| 11 || || <br />
|-<br />
| 12 || 10 || <br />
|-<br />
| 13 || 10 || <br />
|-<br />
|bgcolor = "0088FF" | 14 || 63 || <br />
|-<br />
| rowspan=7 | Middle<br />
| 15 || || Vacuum pump<br />
|-<br />
| 16 || || Overhead crane<br />
|-<br />
| 17 || || Three-phase socket<br />
|-<br />
|bgcolor = "0088FF" | 18 || 25 || Differential switch for circuit breakers 15-17 (?)<br />
|-<br />
| 19 || || Electrical panel 1<br />
|-<br />
| 20 || || Air Treatment Unit<br />
|-<br />
|bgcolor = "0088FF" | 21 || || <br />
|-<br />
| Bottom || || || Global panel switch<br />
<br />
|}<br />
<br />
==L2I floor plan==<br />
The figure below shows a schematic plan of L2I with items relevant to safety.<br /><br />
[[Ficheiro:L2I-Planta-legendas.png|500px|left|Flor plan of L2I.]]</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Experi%C3%AAncia_de_Thomson&diff=6083Experiência de Thomson2025-03-20T09:37:19Z<p>Ist23437: /* Material */</p>
<hr />
<div><big>Determinação experimental da relação \(q/m\) do electrão</big><br />
<br />
{|class="wikitable" style="background-color:#ccddff;"<br />
| Não consegue ver as equações correctamente? Mude https para http no endereço desta página e recarregue.<br />
|}<br />
<br />
=Objectivo do trabalho=<br />
Pretende-se com este trabalho determinar a relação entre a carga e a massa \(q/m\) do [https://pt.wikipedia.org/wiki/El%C3%A9tron electrão]. Para esse fim, vamos estudar a deflexão de um feixe de raios catódicos sob o efeito de um [https://pt.wikipedia.org/wiki/Campo_el%C3%A9trico campo eléctrico] e de um [https://pt.wikipedia.org/wiki/Campo_magn%C3%A9tico campo magnético]. Como as propriedades da trajectória do feixe dependem simultaneamente da massa \(m\) e da carga \(q\) das partículas que o constituem, a análise dessa trajectória permitirá determinar a razão \(q/m\).<br />
<br />
=Introdução=<br />
[[file:TH-crt.png|thumb|upright=0.75 |alt=Tubo de raios catódicos|Tubo de raios catódicos]]Os [https://pt.wikipedia.org/wiki/Raio_cat%C3%B3dico raios catódicos] foram descobertos em 1879 por [https://pt.wikipedia.org/wiki/William_Crookes William Crookes] (1832-1919), mas foi [https://pt.wikipedia.org/wiki/Joseph_John_Thomson Sir J. J. Thomson]<ref>Prémio Nobel da Física de 1906, em reconhecimento dos seus trabalhos teóricos e experimentais na condução da electricidade em gases.</ref> (1856-1940) que, em 1897, relatou as experiências por si realizadas e que permitiram determinar o valor daquela relação. Além disso, estas experiências provaram que os raios catódicos são constituídos por partículas de carga negativa, desde então designadas por [https://pt.wikipedia.org/wiki/El%C3%A9tron electrões]. Neste trabalho iremos reproduzir aproximadamente a experiência de Thomson.<br />
[[file:TH-JJThomson.jpeg|thumb|upright=0.75 |alt=Joseph John Thomson|Joseph John Thomson]]<br />
Thomson foi o primeiro a intuir que uma das unidades fundamentais do átomo era mais de mil vezes menor que o átomo, sugerindo a existência do electrão. Esta ideia teve origem precisamente nas suas explorações das propriedades dos raios cátodicos. <br />
<br />
Em inícios de 1897, Thomson tinha apenas indicações preliminares de que os raios cátodicos poderiam ser deflectidos por campos eléctricos, vindo depois a descobrir que os raios podiam ser desviados de forma fiável se o tubo de descarga fosse evacuado até uma pressão muito baixa. Ao comparar a deflexão dum feixe através de campos eléctricos e magnéticos, obteve as primeiras medições experimentais da relação entre a carga e a massa. O tubo de raios catódicos tornou-se assim o método clássico de medir a relação carga/massa do eletrão. A própria carga só foi medida na [https://pt.wikipedia.org/wiki/Experi%C3%AAncia_da_gota_de_%C3%B3leo experiência da gota de óleo] de [https://pt.wikipedia.org/wiki/Robert_Andrews_Millikan Robert A. Millikan] em 1909.<br />
<br />
Em 1904, Thomson sugeriu um [https://pt.wikipedia.org/wiki/Modelo_at%C3%B4mico_de_Thomson modelo do átomo] ("modelo de pudim de ameixa") na forma de uma esfera de matéria positiva dentro da qual as forças electrostáticas determinariam o posicionamento dos electrões. Para explicar a carga neutra global do átomo, propôs que os electrões estavam distribuídos num mar uniforme de carga positiva. <br />
<br />
Em 1906 Thomson recebeu o Prémio Nobel da Física pelos seus trabalhos sobre a condução de electricidade em gases. Dos seus muitos estudantes, sete vieram também a ganhar um Prémio Nobel: [https://pt.wikipedia.org/wiki/Ernest_Rutherford Ernest Rutherford], [https://pt.wikipedia.org/wiki/William_Lawrence_Bragg Lawrence Bragg], [https://pt.wikipedia.org/wiki/Charles_Glover_Barkla Charles Barkla], [https://pt.wikipedia.org/wiki/Francis_William_Aston Francis Aston], [https://pt.wikipedia.org/wiki/Charles_Thomson_Rees_Wilson Charles T. R. Wilson], [https://pt.wikipedia.org/wiki/Owen_Willans_Richardson Owen Richardson] e [https://pt.wikipedia.org/wiki/Edward_Appleton Edward Victor Appleton].<br />
<br />
=Conceitos fundamentais=<br />
==Campo electrostático==<br />
[[file:fig1-thomson.jpg|thumb|upright=1.0 |alt=Definição dos termos para a geometria de duas cargas |Fig. 1 - Definição dos termos para a geometria de duas cargas]]<br />
Define-se como sendo o campo eléctrico criado por uma distribuição de cargas que ''não evolui no tempo''. Considere-se por exemplo o par de cargas \(q_1\) e \(q_2\) imersas no vácuo, à distância \(r_{12}\) e situadas respetivamente em \(P_1\)e \(P_2\) conforme ilustrado na figura à direita. A força eléctrica que sofre \(q_1\)no ponto \(P_1\)devido a \(q_2\)em \(P_2\)à distância \(r_{12}\)é<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>\mathbf{F}_{P_1,q_1} (q_2, r_{1 2} ) =\frac{1}{4 \pi \varepsilon_0}\frac{q_1 q_2}{r_{1 2}^2} \hat{\mathbf{u}}_{r,P_1} = <br />
- \mathbf{F}_{P_2,q_2} (q_1, r_{1 2} )</math> || \(\quad\quad (1)\)<br />
|}<br />
<br />
em que \(\varepsilon_0\) é designada por [https://pt.wikipedia.org/wiki/Permissividade permitividade eléctrica] do vácuo (\(\varepsilon_0 \simeq 8.854 \cdot 10^{-12}\)F/m) e \(\hat{\mathbf{u}}_{r,P_1}\) é o ''versor'' da distância \(r_{1 2}\) no ponto \(P_1\) (vector unitário dirigido de \(P_2\) para \(P_1\), ver figura).<br />
<br />
Dada uma carga \(q_1\) e um ponto \(P\) a uma distância \(r\), define-se o ''campo eléctrico'' \(\mathbf{E}\) em \(P\) como a força eléctrica por unidade de carga exercida sobre uma carga de prova ou teste, suposta unitária e positiva, colocada em \(P\):<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>\mathbf{E}_P (q_1, r) = \frac{q_1}{4 \pi \varepsilon_0 r^2} \hat{\mathbf{u}}_{r, P} </math> || \(\quad\quad (2)\)<br />
|}<br />
<br />
As unidades do campo eléctrico são o newton/coulomb (N/C) ou, mais habitualmente, o volt/metro (V/m).<br />
<br />
As linhas de força eléctrica geradas por \(q_1\)são radiais e dirigidas para o exterior, se \(q_1>0\) ou para a origem, se \(q_1<0\). Se se colocasse em \(P\) a carga \(q\), a força eléctrica a que esta carga ficaria submetida devido a \(q_1\) seria \(\mathbf{F}_{P,q} (q_1, r ) = q \mathbf{E}\)<br />
ou mais simplesmente:<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>\mathbf{F} = q \mathbf{E}</math> || \(\quad\quad (3)\)<br />
|}<br />
<br />
A expressão ''campo eléctrico'' também define a região do espaço onde se fazem sentir as acções eléctricas.<br />
<br />
==Potencial eléctrico==<br />
<br />
O campo eléctrico e a força eléctrica, que são entidades vectoriais, podem também ser calculadas a partir de uma função capaz de descrever o campo mas de natureza escalar, o ''[https://pt.wikipedia.org/wiki/Potencial_el%C3%A9trico potencial eléctrico]'' \(V\). Para a situação referida acima, o potencial eléctrico criado no ponto \(P\) à distância \(r\) da carga \(q_1\) é calculado por:<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>V_P (q_1, r) = \frac{q_1}{4 \pi \varepsilon_0 r} <br />
</math> || \(\quad\quad (4)\)<br />
|}<br />
No caso de uma distribuição de \(n\) cargas eléctricas \(q_i\) à distância \(r_i\) do ponto \(P\) onde se pretende calcular o campo eléctrico e o potencial, tem-se para o campo eléctrico<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>\mathbf{E}_P = \frac{1}{4 \pi \varepsilon_0 } \sum_{i=1}^n \Big( \frac{q_i}{ r_i^2}\; \hat{\mathbf{u}}_{r_i , P} \Big)</math><br />
|}<br />
<br />
e para o potencial<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math> V_P = \frac{1}{4 \pi \varepsilon_0 } \sum_{i=1}^n \Big( \frac{q_i}{ r_i} \Big) \nonumber</math><br />
|}<br />
<br />
Recorde-se que se se considera uma única carga \(q_1\) positiva, as linhas de força eléctricas são radiais e dirigidas para o exterior. Essas linhas de força são perpendiculares às ''superfícies equipotenciais'', que são esféricas \((r = \mathrm{c.^{te}})\) na equação 4) e concêntricas com as cargas. Atendendo a (4) para dois raios \(r_1\) e \(r_2\) tal que \(r_2 > r_1\) temos \(V(r_2) < V(r_1)\) e portanto as linhas de força dirigem-se para os potenciais decrescentes.<br />
<br />
Considere-se agora o caso de duas cargas \(q_1 > 0\) e \(q_2 < 0\). Enquanto estiverem muito afastadas uma da outra, produzem campos radiais, respetivamente divergindo e convergindo. Se forem colocadas suficientemente próximas, as linhas de força vão sofrer a influência de ambas as cargas. Nesse caso, apenas uma única linha de força é linear, dirigida de \(q_1\) para \(q_2\). Todas as outras, que na vizinhança próxima de cada carga são radiais, acabam por infletir, dirigindo-se de \(q_1\) para \(q_2\). A figura das linhas de força tem simetria de revolução em torno do eixo que contém \(q_1\) e \(q_2\) e é esquematicamente a indicada na figura ao lado. Se o valor absoluto das duas cargas for o mesmo a figura é simétrica em relação ao plano mediatriz das cargas \(q_1\) e \(q_2\).<ref>Para mais exemplos ver https://phet.colorado.edu/en/simulations/charges-and-fields</ref><br />
<br />
[[file:fig2-thomson.jpg|thumb|upright=0.75 |alt=Linhas de força (a vermelho) e superfícies equipotenciais (a verde) de duas cargas simétricas|Fig. 2 - Linhas de força (a vermelho) e superfícies equipotenciais (a verde) de duas cargas simétricas]]<br />
<br />
Se se calcular a diferença de potencial entre dois pontos infinitamente próximos \(P\) e \(P+dP\) devida a uma carga \(q_1\) à distância \(r\) e \(r+dr\) respetivamente, a variação elementar do potencial \(V\) será:<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>d V = V_{P+dP} - V_P = \frac{q_1}{4 \pi \varepsilon_0 r} \big( \frac{1}{r + dr} -\frac{1}{r} \big) \approx \frac{q_1}{4 \pi \varepsilon_0 } \big( - \frac{dr}{r^2} \big) = - \mathbf{E} \cdot d \mathbf{r}</math> || \(\quad\quad (5)\)<br />
|}<br />
<br />
Esta quantidade representa o trabalho elementar (energia) associado ao deslocamento da carga teste (\(q_t=1\,\)C), de \(P\) para \(P+dP\). Para \(q_1 > 0\) \(\mathbf{E}\) e \(\mathbf{dr}\) são paralelos e \(dV < 0\). Isto significa que não será necessário fornecer energia para realizar esse transporte. <br />
De facto, afastar a carga teste da carga \(q_1\) (i.e. ir de \(P\) para \(P+dP\)) leva a uma configuração de cargas \(q_1\) e \(q_t\) energeticamente mais favorável.<ref>Recorde-se que para um campo conservativo o trabalho realizado (que não depende do percurso mas só dos pontos inicial e final) tem um valor simétrico da variação de energia potencial.</ref><br />
<br />
No caso de uma diferença finita de potencial, isto é de uma diferença de potencial entre dois pontos \(P\) e \(Q\) ter-se-á que somar um número infinito de contribuições infinitesimais \(dV_i=- \mathbf{E}_i \cdot d\mathbf{r}_i\) no intervalo de \(P\) a \(Q\):<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>V_Q-V_P = \lim_{n \to \infty } \sum_{i=1}^n dV_i = \lim_{n \to \infty } \sum_{i=1}^n \underbrace{( - \mathbf{E}_i \cdot d\mathbf{r}_i )}_{\overline{PQ}} \rightarrow \int - \mathbf{E} \cdot d\mathbf{r}</math> || \(\quad\quad (6)\)<br />
|}<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>V_P - V_Q = \int_{\overline{PQ}} \mathbf{E} \cdot d \mathbf{r}</math><br />
|}<br />
<br />
e porque \(\mathbf{E}\) (campo electrostático) é um campo conservativo, este integral não vai depender do percurso mas apenas dos pontos extremos, i.e.<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>V_P - V_Q = \int_P^Q \mathbf{E} \cdot d\mathbf{r}</math><br />
|}<br />
<br />
No caso particular de \(E\) ser homogéneo (por exemplo no interior de um [https://pt.wikipedia.org/wiki/Capacitor condensador] plano) na região onde se situam os pontos \(P\) e \(Q\) afastados de uma distância \(D\) obtém-se <br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>V_P - V_Q = \mathbf{E}\cdot\overline{PQ}=E\cdot D</math>|| \(\quad\quad (7)\)<br />
|} <br />
<br />
Para se compreender o significado físico de \(V_P\) imagine-se que \(Q\)é um ponto infinitamente afastado da região em que se faz sentir o campo eléctrico \(\mathbf{E}\).<br />
Nesse ponto, \(r \to \infty\) e \(V_Q=0\) obtendo-se \(V_P = \int_P^\infty \mathbf{E} \cdot d\mathbf{r}\) que permite a seguinte interpretação:<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#ddffdd;" |O potencial eléctrico \(V_P\) é a energia necessária para transportar a carga-teste, sob acção de \(\mathbf{E}\) desde o ponto \(P\) até uma distância suficientemente grande tal que o campo eléctrico não se faça sentir.<br />
|}<br />
<br />
Assim, \(V\) tem sempre o significado de uma diferença de potencial.<br />
<br />
==Energia electrostática==<br />
A [https://pt.wikipedia.org/wiki/Energia_eletrost%C3%A1tica energia associada a uma configuração de cargas] \(q_1\) e \(q_2\) à distância \(r\) é dada por:<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>W = \frac{q_1 q_2}{4 \pi \varepsilon_0 r} = q_1 V_1 = q_2 V_2 = \frac{q_1 V_1 +q_2 V_2}{2} </math>|| \(\quad\quad (8)\)<br />
|}<br />
<br />
em que \(V_1\) é o potencial no ponto \(P_1\) criado pela carga \(q_2\) e \(V_2\) é o potencial no ponto \(P_2\) criado pela carga \(q_1\). <br />
<br />
Recordando a definição do potencial criado por \(n\) cargas eléctricas, podemos generalizar a equação (8) na seguinte forma:<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math><br />
W_E = \frac{1}{2} \sum_{i,j (i\ne j)}^n \frac{ 1 }{4 \pi \varepsilon_0} \frac{ q_i \, q_j }{r_{i\,j}} = <br />
\frac{1}{2} \sum_{i=1}^n q_i \left( \sum_{j \ne i}^n \frac{ q_j }{4 \pi \varepsilon_0 \,r_{i\,j}} \right) =<br />
\frac{1}{2} \sum_{i=1}^n q_i V_i<br />
</math>|| \(\quad\quad (9)\)<br />
|}<br />
que corresponde à energia necessária para criar a distribuição de cargas \(q_i\). A energia \(W_E\) é uma energia potencial porque está associada às posições que as diferentes cargas ocupam, podendo ser recuperada se as cargas se afastarem umas das outras até distâncias \(r \to \infty\).<br />
<br />
==Condutores eléctricos e dieléctricos. Condensador plano==<br />
<br />
[[file:fig-thomson-placa.jpg|thumb|upright=0.75 |alt=Distribuição da carga num condutor carregado |Fig. 3 - Distribuição da carga num condutor carregado]]<br />
[[file:fig-thomson-placas.jpg|thumb|upright=0.75 |alt=Distribuição de cargas e forma do campo eléctrico num condensador |Fig. 4 - Distribuição de cargas e forma do campo eléctrico num condensador]]<br />
<br />
Um material é um ''[https://pt.wikipedia.org/wiki/Condutor_el%C3%A9trico condutor eléctrico ideal]'' se as cargas eléctricas do mesmo sinal em excesso (que o carregam) são livres de se movimentarem no seu interior e à sua superfície. Quando pelo contrário isso não acontece, estamos perante um ''[https://pt.wikipedia.org/wiki/Diel%C3%A9trico dieléctrico]''.<br />
<br />
Assim, se carregarmos um condutor com uma carga total \(Q\) (se \(Q > 0\) significa que se retiram electrões ao condutor inicialmente neutro) essas cargas, todas do mesmo sinal, vão acomodar-se logo que se atinja o equilíbrio electrostático, em posições que são o mais afastadas possíveis umas das outras - ou seja, na superfície exterior do condutor, formando uma "folha" de carga. Pode mostrar-se que \(\mathbf{E}\) no interior do condutor é nulo (enquanto que num dieléctrico \(\mathbf{E} \ne 0\), e que a superfície do condutor é uma ''[https://pt.wikipedia.org/wiki/Equipotencial equipotencial]'': logo, as linhas de força eléctricas são-lhe perpendiculares. Quando um material é carregado, a velocidade com que essas cargas se transferem de todo o volume do condutor para a superfície depende da sua [https://pt.wikipedia.org/wiki/Condutividade_el%C3%A9trica condutividade eléctrica]. Se se considerar um condutor carregado, com geometria plana (uma placa), a carga vai distribuir-se sobre a superfície (Fig. 3).<br />
<br />
Ao colocar-se em frente uma placa idêntica, mas de carga simétrica, haverá uma redistribuição de carga que produz um campo eléctrico entre as placas (Fig. 4). Na região central, as linhas de força são paralelas entre si e o campo eléctrico é homogéneo. Nas extremidades as linhas de força emergem perpendicularmente à superfície mas encurvam, deixando de ser lineares. Esta geometria e distribuição de carga são características de um ''condensador plano''. A diferença de potencial entre as duas placas, afastadas de \(D\) corresponde a \(V_+ \,–\, V_-) = \mathbf{E}\cdot \mathbf{D}\) pois \(\mathbf{E}\) é homogéneo (eq. 7).<br />
<br />
Pode mostrar-se que \(\mathbf{E}\) fica confinado à região entre as placas. Se o condensador fosse infinito (sem extremidades) teríamos três regiões, as duas exteriores ao condensador, onde o campo \(\mathbf{E}\) é nulo, e entre as placas do condensador (também designadas por armaduras), onde o campo seria homogéneo.<br />
<br />
==Efeitos da corrente eléctrica estacionária criada por uma espira==<br />
[[file:fig-fio.jpg|thumb|upright=0.75 |alt=Campo magnético produzido por um fio onde passa corrente |Fig. 5 - Campo magnético produzido por um fio onde passa corrente]]<br />
[[file:fig-espira.jpg|thumb|upright=0.75 |alt=Campo magnético produzido por uma espira circular onde passa corrente |Fig. 6 - Campo magnético produzido por uma espira circular onde passa corrente]]<br />
<br />
A passagem da ''[https://pt.wikipedia.org/wiki/Corrente_el%C3%A9trica corrente eléctrica] estacionária'' (i.e. cuja intensidade não varia no tempo) por um condutor cria um campo magnético \(\mathbf{B}\), além de produzir calor por [https://pt.wikipedia.org/wiki/Lei_de_Joule efeito de Joule]. As ''linhas de força magnética'' produzidas por um fio condutor linear são circulares e concêntricas com o condutor (ver Fig. 5). O módulo de \(B\) num ponto a uma distância \(r\) do fio (medida na perpendicular ao fio) é<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>|\mathbf{B_{\mathrm{fio}}}| = \frac{\mu_0 I}{2\, \pi \, r} </math>|| \(\quad\quad (10)\)<br />
|}<br />
em que \(\mu_0 = 4 \pi× 10^{−7}\) H/m é a ''[https://pt.wikipedia.org/wiki/Permeabilidade_magn%C3%A9tica permeabilidade magnética]'' do vazio. <br />
<br />
No caso de uma espira <ref>Termo que designa um circuito eléctrico fechado</ref> circular, é criado um campo magnético cujas linhas de força são curvas fora do seu eixo e lineares apenas ao longo do eixo. Pode provar-se que o campo magnético criado por uma espira de raio \(r\) percorrida por uma corrente de intensidade \(I\) tem linhas de força fechadas <ref>Mesmo aquelas que só ''fecham'' no infinito</ref>, ao contrário das linhas de força eléctricas. Isto coloca em evidência que \(\mathbf{B}\) nos pontos do plano da espira, mas exteriores a esta, é antiparalelo a \(\mathbf{B}\) no eixo da espira (Fig. 6). O módulo de \(\mathbf{B}\) num ponto do eixo é dado por<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>|\mathbf{B}_{\mathrm{espira}}| = \frac{\mu_0 I}{2 r} \sin^3 \alpha</math>|| \(\quad\quad (11)\)<br />
|}<br />
<br />
==Força de Lorentz==<br />
[[file:Lorentz1.png|thumb|upright=0.75 |alt=Trajectória circular para uma carga positiva \(q\) com velocidade \(\mathbf{v}\)n a presença de um campo magnético \(\mathbf{B}_{in}\) perpendicular. |Fig. 7 - Trajectória circular para uma carga positiva \(q\) com velocidade \(\mathbf{v}\) na presença de um campo magnético \(\mathbf{B}_{in}\) perpendicular.]]<br />
<br />
[[file:Lorentz2.png|thumb|upright=0.75 |alt=Carga positiva \(q\) com velocidade \(\mathbf{v}\) na presença de um campo magnético \(\mathbf{B}_{in}\) e um campo eléctrico \(\mathbf{E}\). Os três vectores são mutuamente perpendiculares e estão orientados de modo que as forças têm sentidos opostos. |Fig. 8 - Carga positiva \(q\) com velocidade \(\mathbf{v}\) na presença de um campo magnético \(\mathbf{B}_{in}\) e um campo eléctrico \(\mathbf{E}\). Os três vectores são mutuamente perpendiculares e estão orientados de modo que as forças têm sentidos opostos.]]<br />
<br />
Uma carga \(q\) animada de uma velocidade \(\mathbf{v}\) numa região em que existe um campo de indução \(\mathbf{B}\) e um campo eléctrico \(\mathbf{E}\) fica submetida a uma [https://pt.wikipedia.org/wiki/For%C3%A7a_de_Lorentz força de Lorentz]<ref>Se a força for apenas de origem magnética, <br />
\(\mathbf{F}_m = q\,(\mathbf{v} \times \mathbf{B})\) pode chamar-se também de ''Laplace''</ref> \(\mathbf{F}\) dada por:<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>\mathbf{F} = q\mathbf{E} + q(\mathbf{v} \times \mathbf{B})</math>|| \(\quad\quad (12)\)<br />
|}<br />
<br />
A força de Lorentz resulta da soma vectorial de uma componente eléctrica e uma componente magnética, que verificam as seguintes propriedades:<br />
<br />
# a força eléctrica \(\mathbf{F_e}=q\mathbf{E}\) tem a mesma direção que o campo eléctrico; se a carga for positiva tem o mesmo sentido, se a carga for negativa tem o sentido oposto;<br />
# a força magnética \(\mathbf{F_e}=q(\mathbf{v} \times \mathbf{B})\) é perpendicular ao plano definido pelos vectores velocidade \((\mathbf{v})\) e campo magnético \((\mathbf{B})\) sendo o seu sentido dado pela regra da mão direita para o produto externo de vectores.<br />
<br />
Quando a velocidade da carga e o campo magnético são mutuamente perpendiculares, a força magnética comporta-se como uma [https://pt.wikipedia.org/wiki/For%C3%A7a_centr%C3%ADpeta força centrípeta] e a carga descreve uma trajectória circular (Fig. 7}) cujo raio se pode calcular igualando os módulos das duas forças \((|\mathbf{F_c}|=|\mathbf{F_m})|\):<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>m\frac{v^2}{R}=qvB \rightarrow R=\frac{mv}{|q|B}</math>|| \(\quad\quad (13)\)<br />
|}<br />
<br />
Um caso particularmente interessante da força de Lorentz verifica-se quando a velocidade da carga é perpendicular tanto ao campo eléctrico como ao magnético. Nesse caso, as duas forças têm a mesma direcção. Adotando uma configuração como a representada na Fig. 8, as forças eléctrica e magnética têm sentidos opostos e podem compensar-se, anulando-se, o que permite que a carga mantenha uma trajectória rectilínea.<br />
<br />
Nesta repetição da experiência de Thomson iremos utilizar estes dois princípios para determinar a razão \(q/m\): <br />
* No primeiro conjunto de medidas, iremos determinar o raio da trajectória de um feixe de raios catódicos na presença de um campo magnético;<br />
* No segundo conjunto de medidas iremos equilibrar as forças de um campo magnético e um eléctrico de modo a que o feixe tenha uma forma aproximadamente rectilínea.<br />
<br />
=Figuras dos aparelhos da montagem experimental=<br />
<br />
{| class="wikitable" style="text-align: center;"<br />
|[[file:fig3-ThomsomEquip.jpg|thumb|center|upright=0.63]]||[[file:fig4-Thomson_Electron-Deflection-Tube-D.jpg|thumb|center|upright=0.75]]<br />
|-<br />
| Fig. 9 - Montagem da Experiência de Thomson com tubo de raios catódicos, suporte e par de bobinas de Helmholtz || Fig. 10 - Trajectória dos electrões sujeitos a um campo magnético perpendicular<br />
|}<br />
<br />
=Procedimento Experimental=<br />
==Material==<br />
<br />
[[file:fig5-TuboTL.jpg|thumb|upright=1.5 |alt=Diagrama do tubo utilizado e geometria das bobinas de Helmholtz. Esquerda: vista lateral, com ligações eléctricas do filamento e da tensão de aceleração. Direita: vista frontal, com ligações das bobinas de Helmholtz. |Fig. 11 - Diagrama do tubo utilizado e geometria das bobinas de Helmholtz. Esquerda: vista lateral, com ligações eléctricas do filamento e da tensão de aceleração. Direita: vista frontal, com ligações das bobinas de Helmholtz.]]<br />
<br />
# Ampola (tubo) de raios catódicos (TRC), [https://www.3bscientific.com/pt/tubo-de-desvio-de-eletrons-d-1000651-u19155-3b-scientific-teltron,p_1003_1349.html modelo TEL 525].<br />
# Fonte de alimentação do TRC, que inclui alimentação de alta tensão contínua (até 5000 V) aplicada aos eléctrodos (cátodo e ânodo) do TRC e alimentação de baixa tensão (6.3 V AC) para o filamento do TRC.<br />
# Par de bobinas que envolvem a parte esférica do TRC na configuração de Helmholtz (para criar um campo magnético aproximadamente homogéneo na região central entre as bobinas, de raio médio\(r\) e afastadas de \(r\)uma da outra).<br />
# Fonte de alimentação de corrente '''contínua''' (em modo DC) para as bobinas.<br />
# Multímetro (como amperímetro) a instalar em '''série''' no circuito das bobinas.<br />
<br />
O tubo TRC tem um filamento alimentado por 6.3 V (em modo AC). Este filamento emite electrões por efeito termiónico. <br />
Entre o ânodo e o cátodo do tubo estabelecem-se diferenças de potencial \( (V_+ - V_-) = U_a\). Os electrões são acelerados entre o cátodo e o ânodo e a sua velocidade à saída do ânodo é função de \(U_a\). <br />
<br />
Ao entrarem na parte esférica do tubo, os electrões podem ser deflectidos por ''campos magnéticos'' provocados por correntes que percorrem as bobinas de Helmholtz e/ou por ''campos eléctricos'' devidos à aplicação de tensão entre duas placas paralelas ligadas aos pontos 1 e 2 do diagrama (ver figura).<br />
<br />
O campo de indução magnética \(B\) devido às bobinas de Helmholtz é aproximadamente uniforme na região central entre as bobinas, e para uma corrente \(I\) é dado por <ref>No sistema SI, a unidade de campo magnético é o Tesla (T), sendo <br />
1 T=1 Weber/m\(^2\).</ref>:<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>B = \left(\frac{4}{5}\right)^{3/2} \cdot \frac{\mu_0 n I}{r} = \frac{32 \pi n }{5 \sqrt{5}} \cdot \frac{I}{r} \cdot 10^{-7}\textrm{ Weber/m}^{2}</math>|| \(\quad\quad (14)\)<br />
|}<br />
onde \(n = 320\) espiras, \(r= 0.068\) m e \(r = d/2\). Note que o valor \(d\) nesta fórmula se refere ao ''diâmetro'' das bobinas (ver Fig. 11). Mais abaixo é usada a mesma designação para a distância entre as placas da âmpola, valor que deve ser medido.<br />
<br />
{|class="wikitable" style="background-color:#ffcccc;"<br />
| [[file:Electrocution-Safety.png|thumb|upright=0.5]] || '''Atenção:''' Este trabalho envolve o uso de fontes de alta tensão (até 5 kV) e correntes eléctricas elevadas (até 1 A). Assegure-se de que cumpre rigorosamente as medidas de segurança com equipamentos eléctricos, em particular:<br />
* Compreenda os [https://pt.wikipedia.org/wiki/Choque_el%C3%A9trico riscos inerentes] a tensões e correntes elevadas<br />
* Não pegue nos cabos ou conectores pela partes condutoras, apenas pelas partes isoladas<br />
* Assegure-se de que as fontes de tensão e corrente estão dsligadas antes de efectuar qualquer alteração nas montagens eléctricas<br />
* Em caso de dúvida, chame o docente<br />
|}<br />
<br />
==Determinação de \(q/m\) por deflexão magnética==<br />
===Trajectórias de partículas carregadas sujeitas a um campo magnético constante===<br />
Quando se aplica uma tensão \(U_a\)entre o ânodo e o cátodo (sem aplicar tensão entre os pontos 1 e 2 representados na figura acima), pode admitir-se que a velocidade final \(v\) dos electrões ao abandonarem o ânodo é dada pela seguinte expressão <br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>q\, U_a = \frac{1}{2} m \, v^2</math>|| \(\quad\quad (15)\)<br />
|}<br />
em que \(q\) é a carga do electrão e\(m\)a sua massa.<br />
<br />
Os electrões entram, com velocidade horizontal, na parte esférica do tubo, onde são deflectidos pelo campo magnético \(\mathbf{B}\) (com \(\mathbf{B}\perp\mathbf{v})\). A sua trajectória passa então a ser circular, com raio \(R\) verificando-se:<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>B \, q\, v = \frac{m\,v^2}{R} </math>|| \(\quad\quad (16)\)<br />
|}<br />
As trajectórias dos electrões podem ser visualizadas numa escala graduada feita de material fluorescente. A origem do reticulado está situada aproximadamente no início da zona sujeita ao campo \(\mathbf{B}\). Combinando (15) e (16) obtém-se uma expressão para a relação \(q/m\):<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>\frac{q}{m} = \frac{2\, U_a}{B^2\,R^2} </math>|| \(\quad\quad (17)\)<br />
|}<br />
<br />
em que:<br />
*\(U_a\) – impõe-se e mede-se diretamente no voltímetro da fonte de tensão.<br />
*\(B\) – calcula-se, para uma dada corrente \(I\) a partir da expressão (14).<br />
*\(R\) – determina-se por leitura no écran fluorescente, das coordenadas de posição \(y\) (horizontal) e \(z\) (vertical) de pontos do feixe. Por construção do tubo verifica-se:<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>R = \frac{y^2 + z^2}{2 \, z} </math>|| \(\quad\quad (18)\)<br />
|}<br />
<br />
===Modo de proceder===<br />
<br />
# Montar os circuitos eléctricos de acordo com a Fig. 11 (Secção [[Experiência_de_Thomson#Material|Material]]). Note que as ligações das bobinas devem garantir que a corrente eléctrica é percorrida no mesmo sentido, em ambas: para isso, deve usar os conectores na ordem \(A\rightarrow Z\) numa bobina e na ordem inversa na outra bobina. Chamar o docente para verificação, '''antes de ligar os aparelhos'''.<br />
# Verifique qual é o valor máximo da tensão disponível na fonte de alta tensão. Escolha um valor ligeiramente inferior.<br />
# Ajustar a corrente das bobinas de Helmholtz \(I_+\) de modo a que a circunferência passe por um ponto bem determinado. <ref>Utilize de preferência os maiores valores possíveis para o raio \(R\) de forma a que o feixe se encontre na zona central entre as bobines.</ref> Calcule \(R\). Inverta o sentido da corrente e determine um novo \(I_-\) para o mesmo raio \(R\). Tomando \(I_{\textrm{medio}} = (I_+ + I_-)/2\), calcule o campo magnético \(B_{\textrm{medio}}\). Utilize a semi-diferença, \((I_+ - I_-)/2\) para a estimativa das incertezas \(\delta I_{\textrm{medio}}\) e \(\delta B_{\textrm{medio}}\).<br />
# Repita o ponto 2) para quatro novos valores de\(R\). <br />
# Repetir 1), 2) e 3) e para os mesmos \(R\) para dois valores inferiores de tensão, afastados por exemplo de 500 V entre si.<br />
# Apresente os valores de \(q/m\) para os 15 pares de determinações. Calcule a média desses valores, assim como a incerteza da média.<br />
# Para um dos pares de pontos, estime a contribuição relativa das incertezas das grandezas que mediu para a incerteza total. Compare este erro assim calculado com a incerteza calculada a partir dos 15 valores calculados. Apresente para cada raio o valor de \(q/m\) assim como o erro associado a cada uma das determinações. Compare e comente os resultados.<br />
# Apresente um valor final para \(q/m\), tendo em conta que se trata de uma ''combinação de resultados'' (e não uma média simples). Estime a precisão e a exatidão obtida nas determinações que realizou.<br />
<br />
==Determinação de \(q/m\) por deflexão magnética e eléctrica quase compensada==<br />
<br />
===Situação de equilíbrio entre as interacções eléctrica e magnética===<br />
<br />
Se, na força de Lorentz, os dois termos se equilibrarem — ou seja, se as forças electrostática e magnética forem de igual módulo e de sentidos opostos — a carga \(q\) não é desviada da sua trajectória. No nosso caso, em que \(\mathbf{B} \perp \mathbf{v}\), a condição de equilíbrio é dada por <math> |\mathbf{E}| = v\, |\mathbf{B}|</math>.<br />
<br />
===Montagem a efectuar===<br />
<br />
[[file:fig6-TuboTLE.jpg|thumb|upright=1.0 |alt=Deflexão magnética e eléctrica quase compensada: ligações eléctricas do filamento, da tensão de aceleração e das placas. |Fig. 12 - Deflexão magnética e eléctrica quase compensada: ligações eléctricas do filamento, da tensão de aceleração e das placas.]]<br />
<br />
Aproveitando a montagem já efectuada no ponto anterior, ligue agora os terminais no topo e na base da âmpola (ver figura) à fonte de alta tensão que gera a tensão \(U_a\) produzindo assim na região do écran fluorescente um campo eléctrico. Fazendo com que as bobinas sejam percorridas por uma corrente com intensidade e "sentido" convenientes, podemos obter uma força de origem magnética anti-paralela à provocada pelo campo \(\mathbf{E}\). Deste modo, a trajectória visualizada no écran será aproximadamente retilínea, sendo a condição de equilíbrio dada por:<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math> |\vec{E}| = v\, |\vec{B}| = \frac{U_a}{d}</math>|| \(\quad\quad (19)\)<br />
|}<br />
onde \(d\) é a distância entre as placas do écran fluorescente e \(U_a\) a tensão entre as mesmas, que é como se disse igual à tensão de aceleração. A equação acima permite-nos calcular a velocidade dos electrões, uma vez que podemos conhecer os valores de todas as outras variáveis aí intervenientes. O conhecimento de \(v\) permite-nos calcular \(q/m\) tendo em conta que, segundo <math>qU_a=mv^2/2</math>, deverá ser:<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>\frac{q}{m} = \frac{v^2}{2} \; \frac{1}{U_a}<br />
</math>|| \(\quad\quad (20)\)<br />
|}<br />
<br />
Eliminando o termo <math>v</math> obtemos finalmente:<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>\frac{q}{m} = \frac{1}{2} \; \frac{U_a}{B^2d^2}<br />
</math>|| \(\quad\quad (21)\)<br />
|}<br />
<br />
===Modo de proceder===<br />
<br />
# Para cada uma das quatro tensões de trabalho \(U_a\)já referidas, aplicadas agora também às placas que produzem o campo eléctrico, determine o valor de \(B\) (a partir de \(I\) que conduz ao anulamento das forças de origem eléctrica e magnética.<br />
# Inverta o sentido dos campos eléctricos e magnéticos e repita a determinação do valor de \(B\).<br />
# Apresente os valores de \(q/m\). Analise as diferentes contribuições para a incerteza total. Estime o valor da relação carga/massa do electrão, assim como a precisão e a exatidão obtida nas determinações que realizou.<br />
# Observe a trajectória quando as forças de origem eléctrica e magnética não se compensam. Comente.<br />
<br />
=Notas=<br />
<references /><br />
<br />
=Ligações externas=<br />
* [https://www.youtube.com/watch?v=5YYVnHN7xwM Charge to mass ratio of an electron] Animação da experiência de Thomson<br />
* [https://www.youtube.com/watch?v=ZxtPGN8Ipa0 Motion of electric charges in a uniform magnetic field] Animação do movimento de cargas em campos magnéticos uniformes<br />
* [https://www.youtube.com/watch?v=q4Hjqvyv-Ek Deflection of an electron beam in a magnetic field] Deflexão de um feixe de raios catódicos num campo magnético</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Experi%C3%AAncia_de_Thomson&diff=6082Experiência de Thomson2025-03-20T09:35:09Z<p>Ist23437: /* Material */</p>
<hr />
<div><big>Determinação experimental da relação \(q/m\) do electrão</big><br />
<br />
{|class="wikitable" style="background-color:#ccddff;"<br />
| Não consegue ver as equações correctamente? Mude https para http no endereço desta página e recarregue.<br />
|}<br />
<br />
=Objectivo do trabalho=<br />
Pretende-se com este trabalho determinar a relação entre a carga e a massa \(q/m\) do [https://pt.wikipedia.org/wiki/El%C3%A9tron electrão]. Para esse fim, vamos estudar a deflexão de um feixe de raios catódicos sob o efeito de um [https://pt.wikipedia.org/wiki/Campo_el%C3%A9trico campo eléctrico] e de um [https://pt.wikipedia.org/wiki/Campo_magn%C3%A9tico campo magnético]. Como as propriedades da trajectória do feixe dependem simultaneamente da massa \(m\) e da carga \(q\) das partículas que o constituem, a análise dessa trajectória permitirá determinar a razão \(q/m\).<br />
<br />
=Introdução=<br />
[[file:TH-crt.png|thumb|upright=0.75 |alt=Tubo de raios catódicos|Tubo de raios catódicos]]Os [https://pt.wikipedia.org/wiki/Raio_cat%C3%B3dico raios catódicos] foram descobertos em 1879 por [https://pt.wikipedia.org/wiki/William_Crookes William Crookes] (1832-1919), mas foi [https://pt.wikipedia.org/wiki/Joseph_John_Thomson Sir J. J. Thomson]<ref>Prémio Nobel da Física de 1906, em reconhecimento dos seus trabalhos teóricos e experimentais na condução da electricidade em gases.</ref> (1856-1940) que, em 1897, relatou as experiências por si realizadas e que permitiram determinar o valor daquela relação. Além disso, estas experiências provaram que os raios catódicos são constituídos por partículas de carga negativa, desde então designadas por [https://pt.wikipedia.org/wiki/El%C3%A9tron electrões]. Neste trabalho iremos reproduzir aproximadamente a experiência de Thomson.<br />
[[file:TH-JJThomson.jpeg|thumb|upright=0.75 |alt=Joseph John Thomson|Joseph John Thomson]]<br />
Thomson foi o primeiro a intuir que uma das unidades fundamentais do átomo era mais de mil vezes menor que o átomo, sugerindo a existência do electrão. Esta ideia teve origem precisamente nas suas explorações das propriedades dos raios cátodicos. <br />
<br />
Em inícios de 1897, Thomson tinha apenas indicações preliminares de que os raios cátodicos poderiam ser deflectidos por campos eléctricos, vindo depois a descobrir que os raios podiam ser desviados de forma fiável se o tubo de descarga fosse evacuado até uma pressão muito baixa. Ao comparar a deflexão dum feixe através de campos eléctricos e magnéticos, obteve as primeiras medições experimentais da relação entre a carga e a massa. O tubo de raios catódicos tornou-se assim o método clássico de medir a relação carga/massa do eletrão. A própria carga só foi medida na [https://pt.wikipedia.org/wiki/Experi%C3%AAncia_da_gota_de_%C3%B3leo experiência da gota de óleo] de [https://pt.wikipedia.org/wiki/Robert_Andrews_Millikan Robert A. Millikan] em 1909.<br />
<br />
Em 1904, Thomson sugeriu um [https://pt.wikipedia.org/wiki/Modelo_at%C3%B4mico_de_Thomson modelo do átomo] ("modelo de pudim de ameixa") na forma de uma esfera de matéria positiva dentro da qual as forças electrostáticas determinariam o posicionamento dos electrões. Para explicar a carga neutra global do átomo, propôs que os electrões estavam distribuídos num mar uniforme de carga positiva. <br />
<br />
Em 1906 Thomson recebeu o Prémio Nobel da Física pelos seus trabalhos sobre a condução de electricidade em gases. Dos seus muitos estudantes, sete vieram também a ganhar um Prémio Nobel: [https://pt.wikipedia.org/wiki/Ernest_Rutherford Ernest Rutherford], [https://pt.wikipedia.org/wiki/William_Lawrence_Bragg Lawrence Bragg], [https://pt.wikipedia.org/wiki/Charles_Glover_Barkla Charles Barkla], [https://pt.wikipedia.org/wiki/Francis_William_Aston Francis Aston], [https://pt.wikipedia.org/wiki/Charles_Thomson_Rees_Wilson Charles T. R. Wilson], [https://pt.wikipedia.org/wiki/Owen_Willans_Richardson Owen Richardson] e [https://pt.wikipedia.org/wiki/Edward_Appleton Edward Victor Appleton].<br />
<br />
=Conceitos fundamentais=<br />
==Campo electrostático==<br />
[[file:fig1-thomson.jpg|thumb|upright=1.0 |alt=Definição dos termos para a geometria de duas cargas |Fig. 1 - Definição dos termos para a geometria de duas cargas]]<br />
Define-se como sendo o campo eléctrico criado por uma distribuição de cargas que ''não evolui no tempo''. Considere-se por exemplo o par de cargas \(q_1\) e \(q_2\) imersas no vácuo, à distância \(r_{12}\) e situadas respetivamente em \(P_1\)e \(P_2\) conforme ilustrado na figura à direita. A força eléctrica que sofre \(q_1\)no ponto \(P_1\)devido a \(q_2\)em \(P_2\)à distância \(r_{12}\)é<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>\mathbf{F}_{P_1,q_1} (q_2, r_{1 2} ) =\frac{1}{4 \pi \varepsilon_0}\frac{q_1 q_2}{r_{1 2}^2} \hat{\mathbf{u}}_{r,P_1} = <br />
- \mathbf{F}_{P_2,q_2} (q_1, r_{1 2} )</math> || \(\quad\quad (1)\)<br />
|}<br />
<br />
em que \(\varepsilon_0\) é designada por [https://pt.wikipedia.org/wiki/Permissividade permitividade eléctrica] do vácuo (\(\varepsilon_0 \simeq 8.854 \cdot 10^{-12}\)F/m) e \(\hat{\mathbf{u}}_{r,P_1}\) é o ''versor'' da distância \(r_{1 2}\) no ponto \(P_1\) (vector unitário dirigido de \(P_2\) para \(P_1\), ver figura).<br />
<br />
Dada uma carga \(q_1\) e um ponto \(P\) a uma distância \(r\), define-se o ''campo eléctrico'' \(\mathbf{E}\) em \(P\) como a força eléctrica por unidade de carga exercida sobre uma carga de prova ou teste, suposta unitária e positiva, colocada em \(P\):<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>\mathbf{E}_P (q_1, r) = \frac{q_1}{4 \pi \varepsilon_0 r^2} \hat{\mathbf{u}}_{r, P} </math> || \(\quad\quad (2)\)<br />
|}<br />
<br />
As unidades do campo eléctrico são o newton/coulomb (N/C) ou, mais habitualmente, o volt/metro (V/m).<br />
<br />
As linhas de força eléctrica geradas por \(q_1\)são radiais e dirigidas para o exterior, se \(q_1>0\) ou para a origem, se \(q_1<0\). Se se colocasse em \(P\) a carga \(q\), a força eléctrica a que esta carga ficaria submetida devido a \(q_1\) seria \(\mathbf{F}_{P,q} (q_1, r ) = q \mathbf{E}\)<br />
ou mais simplesmente:<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>\mathbf{F} = q \mathbf{E}</math> || \(\quad\quad (3)\)<br />
|}<br />
<br />
A expressão ''campo eléctrico'' também define a região do espaço onde se fazem sentir as acções eléctricas.<br />
<br />
==Potencial eléctrico==<br />
<br />
O campo eléctrico e a força eléctrica, que são entidades vectoriais, podem também ser calculadas a partir de uma função capaz de descrever o campo mas de natureza escalar, o ''[https://pt.wikipedia.org/wiki/Potencial_el%C3%A9trico potencial eléctrico]'' \(V\). Para a situação referida acima, o potencial eléctrico criado no ponto \(P\) à distância \(r\) da carga \(q_1\) é calculado por:<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>V_P (q_1, r) = \frac{q_1}{4 \pi \varepsilon_0 r} <br />
</math> || \(\quad\quad (4)\)<br />
|}<br />
No caso de uma distribuição de \(n\) cargas eléctricas \(q_i\) à distância \(r_i\) do ponto \(P\) onde se pretende calcular o campo eléctrico e o potencial, tem-se para o campo eléctrico<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>\mathbf{E}_P = \frac{1}{4 \pi \varepsilon_0 } \sum_{i=1}^n \Big( \frac{q_i}{ r_i^2}\; \hat{\mathbf{u}}_{r_i , P} \Big)</math><br />
|}<br />
<br />
e para o potencial<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math> V_P = \frac{1}{4 \pi \varepsilon_0 } \sum_{i=1}^n \Big( \frac{q_i}{ r_i} \Big) \nonumber</math><br />
|}<br />
<br />
Recorde-se que se se considera uma única carga \(q_1\) positiva, as linhas de força eléctricas são radiais e dirigidas para o exterior. Essas linhas de força são perpendiculares às ''superfícies equipotenciais'', que são esféricas \((r = \mathrm{c.^{te}})\) na equação 4) e concêntricas com as cargas. Atendendo a (4) para dois raios \(r_1\) e \(r_2\) tal que \(r_2 > r_1\) temos \(V(r_2) < V(r_1)\) e portanto as linhas de força dirigem-se para os potenciais decrescentes.<br />
<br />
Considere-se agora o caso de duas cargas \(q_1 > 0\) e \(q_2 < 0\). Enquanto estiverem muito afastadas uma da outra, produzem campos radiais, respetivamente divergindo e convergindo. Se forem colocadas suficientemente próximas, as linhas de força vão sofrer a influência de ambas as cargas. Nesse caso, apenas uma única linha de força é linear, dirigida de \(q_1\) para \(q_2\). Todas as outras, que na vizinhança próxima de cada carga são radiais, acabam por infletir, dirigindo-se de \(q_1\) para \(q_2\). A figura das linhas de força tem simetria de revolução em torno do eixo que contém \(q_1\) e \(q_2\) e é esquematicamente a indicada na figura ao lado. Se o valor absoluto das duas cargas for o mesmo a figura é simétrica em relação ao plano mediatriz das cargas \(q_1\) e \(q_2\).<ref>Para mais exemplos ver https://phet.colorado.edu/en/simulations/charges-and-fields</ref><br />
<br />
[[file:fig2-thomson.jpg|thumb|upright=0.75 |alt=Linhas de força (a vermelho) e superfícies equipotenciais (a verde) de duas cargas simétricas|Fig. 2 - Linhas de força (a vermelho) e superfícies equipotenciais (a verde) de duas cargas simétricas]]<br />
<br />
Se se calcular a diferença de potencial entre dois pontos infinitamente próximos \(P\) e \(P+dP\) devida a uma carga \(q_1\) à distância \(r\) e \(r+dr\) respetivamente, a variação elementar do potencial \(V\) será:<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>d V = V_{P+dP} - V_P = \frac{q_1}{4 \pi \varepsilon_0 r} \big( \frac{1}{r + dr} -\frac{1}{r} \big) \approx \frac{q_1}{4 \pi \varepsilon_0 } \big( - \frac{dr}{r^2} \big) = - \mathbf{E} \cdot d \mathbf{r}</math> || \(\quad\quad (5)\)<br />
|}<br />
<br />
Esta quantidade representa o trabalho elementar (energia) associado ao deslocamento da carga teste (\(q_t=1\,\)C), de \(P\) para \(P+dP\). Para \(q_1 > 0\) \(\mathbf{E}\) e \(\mathbf{dr}\) são paralelos e \(dV < 0\). Isto significa que não será necessário fornecer energia para realizar esse transporte. <br />
De facto, afastar a carga teste da carga \(q_1\) (i.e. ir de \(P\) para \(P+dP\)) leva a uma configuração de cargas \(q_1\) e \(q_t\) energeticamente mais favorável.<ref>Recorde-se que para um campo conservativo o trabalho realizado (que não depende do percurso mas só dos pontos inicial e final) tem um valor simétrico da variação de energia potencial.</ref><br />
<br />
No caso de uma diferença finita de potencial, isto é de uma diferença de potencial entre dois pontos \(P\) e \(Q\) ter-se-á que somar um número infinito de contribuições infinitesimais \(dV_i=- \mathbf{E}_i \cdot d\mathbf{r}_i\) no intervalo de \(P\) a \(Q\):<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>V_Q-V_P = \lim_{n \to \infty } \sum_{i=1}^n dV_i = \lim_{n \to \infty } \sum_{i=1}^n \underbrace{( - \mathbf{E}_i \cdot d\mathbf{r}_i )}_{\overline{PQ}} \rightarrow \int - \mathbf{E} \cdot d\mathbf{r}</math> || \(\quad\quad (6)\)<br />
|}<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>V_P - V_Q = \int_{\overline{PQ}} \mathbf{E} \cdot d \mathbf{r}</math><br />
|}<br />
<br />
e porque \(\mathbf{E}\) (campo electrostático) é um campo conservativo, este integral não vai depender do percurso mas apenas dos pontos extremos, i.e.<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>V_P - V_Q = \int_P^Q \mathbf{E} \cdot d\mathbf{r}</math><br />
|}<br />
<br />
No caso particular de \(E\) ser homogéneo (por exemplo no interior de um [https://pt.wikipedia.org/wiki/Capacitor condensador] plano) na região onde se situam os pontos \(P\) e \(Q\) afastados de uma distância \(D\) obtém-se <br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>V_P - V_Q = \mathbf{E}\cdot\overline{PQ}=E\cdot D</math>|| \(\quad\quad (7)\)<br />
|} <br />
<br />
Para se compreender o significado físico de \(V_P\) imagine-se que \(Q\)é um ponto infinitamente afastado da região em que se faz sentir o campo eléctrico \(\mathbf{E}\).<br />
Nesse ponto, \(r \to \infty\) e \(V_Q=0\) obtendo-se \(V_P = \int_P^\infty \mathbf{E} \cdot d\mathbf{r}\) que permite a seguinte interpretação:<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#ddffdd;" |O potencial eléctrico \(V_P\) é a energia necessária para transportar a carga-teste, sob acção de \(\mathbf{E}\) desde o ponto \(P\) até uma distância suficientemente grande tal que o campo eléctrico não se faça sentir.<br />
|}<br />
<br />
Assim, \(V\) tem sempre o significado de uma diferença de potencial.<br />
<br />
==Energia electrostática==<br />
A [https://pt.wikipedia.org/wiki/Energia_eletrost%C3%A1tica energia associada a uma configuração de cargas] \(q_1\) e \(q_2\) à distância \(r\) é dada por:<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>W = \frac{q_1 q_2}{4 \pi \varepsilon_0 r} = q_1 V_1 = q_2 V_2 = \frac{q_1 V_1 +q_2 V_2}{2} </math>|| \(\quad\quad (8)\)<br />
|}<br />
<br />
em que \(V_1\) é o potencial no ponto \(P_1\) criado pela carga \(q_2\) e \(V_2\) é o potencial no ponto \(P_2\) criado pela carga \(q_1\). <br />
<br />
Recordando a definição do potencial criado por \(n\) cargas eléctricas, podemos generalizar a equação (8) na seguinte forma:<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math><br />
W_E = \frac{1}{2} \sum_{i,j (i\ne j)}^n \frac{ 1 }{4 \pi \varepsilon_0} \frac{ q_i \, q_j }{r_{i\,j}} = <br />
\frac{1}{2} \sum_{i=1}^n q_i \left( \sum_{j \ne i}^n \frac{ q_j }{4 \pi \varepsilon_0 \,r_{i\,j}} \right) =<br />
\frac{1}{2} \sum_{i=1}^n q_i V_i<br />
</math>|| \(\quad\quad (9)\)<br />
|}<br />
que corresponde à energia necessária para criar a distribuição de cargas \(q_i\). A energia \(W_E\) é uma energia potencial porque está associada às posições que as diferentes cargas ocupam, podendo ser recuperada se as cargas se afastarem umas das outras até distâncias \(r \to \infty\).<br />
<br />
==Condutores eléctricos e dieléctricos. Condensador plano==<br />
<br />
[[file:fig-thomson-placa.jpg|thumb|upright=0.75 |alt=Distribuição da carga num condutor carregado |Fig. 3 - Distribuição da carga num condutor carregado]]<br />
[[file:fig-thomson-placas.jpg|thumb|upright=0.75 |alt=Distribuição de cargas e forma do campo eléctrico num condensador |Fig. 4 - Distribuição de cargas e forma do campo eléctrico num condensador]]<br />
<br />
Um material é um ''[https://pt.wikipedia.org/wiki/Condutor_el%C3%A9trico condutor eléctrico ideal]'' se as cargas eléctricas do mesmo sinal em excesso (que o carregam) são livres de se movimentarem no seu interior e à sua superfície. Quando pelo contrário isso não acontece, estamos perante um ''[https://pt.wikipedia.org/wiki/Diel%C3%A9trico dieléctrico]''.<br />
<br />
Assim, se carregarmos um condutor com uma carga total \(Q\) (se \(Q > 0\) significa que se retiram electrões ao condutor inicialmente neutro) essas cargas, todas do mesmo sinal, vão acomodar-se logo que se atinja o equilíbrio electrostático, em posições que são o mais afastadas possíveis umas das outras - ou seja, na superfície exterior do condutor, formando uma "folha" de carga. Pode mostrar-se que \(\mathbf{E}\) no interior do condutor é nulo (enquanto que num dieléctrico \(\mathbf{E} \ne 0\), e que a superfície do condutor é uma ''[https://pt.wikipedia.org/wiki/Equipotencial equipotencial]'': logo, as linhas de força eléctricas são-lhe perpendiculares. Quando um material é carregado, a velocidade com que essas cargas se transferem de todo o volume do condutor para a superfície depende da sua [https://pt.wikipedia.org/wiki/Condutividade_el%C3%A9trica condutividade eléctrica]. Se se considerar um condutor carregado, com geometria plana (uma placa), a carga vai distribuir-se sobre a superfície (Fig. 3).<br />
<br />
Ao colocar-se em frente uma placa idêntica, mas de carga simétrica, haverá uma redistribuição de carga que produz um campo eléctrico entre as placas (Fig. 4). Na região central, as linhas de força são paralelas entre si e o campo eléctrico é homogéneo. Nas extremidades as linhas de força emergem perpendicularmente à superfície mas encurvam, deixando de ser lineares. Esta geometria e distribuição de carga são características de um ''condensador plano''. A diferença de potencial entre as duas placas, afastadas de \(D\) corresponde a \(V_+ \,–\, V_-) = \mathbf{E}\cdot \mathbf{D}\) pois \(\mathbf{E}\) é homogéneo (eq. 7).<br />
<br />
Pode mostrar-se que \(\mathbf{E}\) fica confinado à região entre as placas. Se o condensador fosse infinito (sem extremidades) teríamos três regiões, as duas exteriores ao condensador, onde o campo \(\mathbf{E}\) é nulo, e entre as placas do condensador (também designadas por armaduras), onde o campo seria homogéneo.<br />
<br />
==Efeitos da corrente eléctrica estacionária criada por uma espira==<br />
[[file:fig-fio.jpg|thumb|upright=0.75 |alt=Campo magnético produzido por um fio onde passa corrente |Fig. 5 - Campo magnético produzido por um fio onde passa corrente]]<br />
[[file:fig-espira.jpg|thumb|upright=0.75 |alt=Campo magnético produzido por uma espira circular onde passa corrente |Fig. 6 - Campo magnético produzido por uma espira circular onde passa corrente]]<br />
<br />
A passagem da ''[https://pt.wikipedia.org/wiki/Corrente_el%C3%A9trica corrente eléctrica] estacionária'' (i.e. cuja intensidade não varia no tempo) por um condutor cria um campo magnético \(\mathbf{B}\), além de produzir calor por [https://pt.wikipedia.org/wiki/Lei_de_Joule efeito de Joule]. As ''linhas de força magnética'' produzidas por um fio condutor linear são circulares e concêntricas com o condutor (ver Fig. 5). O módulo de \(B\) num ponto a uma distância \(r\) do fio (medida na perpendicular ao fio) é<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>|\mathbf{B_{\mathrm{fio}}}| = \frac{\mu_0 I}{2\, \pi \, r} </math>|| \(\quad\quad (10)\)<br />
|}<br />
em que \(\mu_0 = 4 \pi× 10^{−7}\) H/m é a ''[https://pt.wikipedia.org/wiki/Permeabilidade_magn%C3%A9tica permeabilidade magnética]'' do vazio. <br />
<br />
No caso de uma espira <ref>Termo que designa um circuito eléctrico fechado</ref> circular, é criado um campo magnético cujas linhas de força são curvas fora do seu eixo e lineares apenas ao longo do eixo. Pode provar-se que o campo magnético criado por uma espira de raio \(r\) percorrida por uma corrente de intensidade \(I\) tem linhas de força fechadas <ref>Mesmo aquelas que só ''fecham'' no infinito</ref>, ao contrário das linhas de força eléctricas. Isto coloca em evidência que \(\mathbf{B}\) nos pontos do plano da espira, mas exteriores a esta, é antiparalelo a \(\mathbf{B}\) no eixo da espira (Fig. 6). O módulo de \(\mathbf{B}\) num ponto do eixo é dado por<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>|\mathbf{B}_{\mathrm{espira}}| = \frac{\mu_0 I}{2 r} \sin^3 \alpha</math>|| \(\quad\quad (11)\)<br />
|}<br />
<br />
==Força de Lorentz==<br />
[[file:Lorentz1.png|thumb|upright=0.75 |alt=Trajectória circular para uma carga positiva \(q\) com velocidade \(\mathbf{v}\)n a presença de um campo magnético \(\mathbf{B}_{in}\) perpendicular. |Fig. 7 - Trajectória circular para uma carga positiva \(q\) com velocidade \(\mathbf{v}\) na presença de um campo magnético \(\mathbf{B}_{in}\) perpendicular.]]<br />
<br />
[[file:Lorentz2.png|thumb|upright=0.75 |alt=Carga positiva \(q\) com velocidade \(\mathbf{v}\) na presença de um campo magnético \(\mathbf{B}_{in}\) e um campo eléctrico \(\mathbf{E}\). Os três vectores são mutuamente perpendiculares e estão orientados de modo que as forças têm sentidos opostos. |Fig. 8 - Carga positiva \(q\) com velocidade \(\mathbf{v}\) na presença de um campo magnético \(\mathbf{B}_{in}\) e um campo eléctrico \(\mathbf{E}\). Os três vectores são mutuamente perpendiculares e estão orientados de modo que as forças têm sentidos opostos.]]<br />
<br />
Uma carga \(q\) animada de uma velocidade \(\mathbf{v}\) numa região em que existe um campo de indução \(\mathbf{B}\) e um campo eléctrico \(\mathbf{E}\) fica submetida a uma [https://pt.wikipedia.org/wiki/For%C3%A7a_de_Lorentz força de Lorentz]<ref>Se a força for apenas de origem magnética, <br />
\(\mathbf{F}_m = q\,(\mathbf{v} \times \mathbf{B})\) pode chamar-se também de ''Laplace''</ref> \(\mathbf{F}\) dada por:<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>\mathbf{F} = q\mathbf{E} + q(\mathbf{v} \times \mathbf{B})</math>|| \(\quad\quad (12)\)<br />
|}<br />
<br />
A força de Lorentz resulta da soma vectorial de uma componente eléctrica e uma componente magnética, que verificam as seguintes propriedades:<br />
<br />
# a força eléctrica \(\mathbf{F_e}=q\mathbf{E}\) tem a mesma direção que o campo eléctrico; se a carga for positiva tem o mesmo sentido, se a carga for negativa tem o sentido oposto;<br />
# a força magnética \(\mathbf{F_e}=q(\mathbf{v} \times \mathbf{B})\) é perpendicular ao plano definido pelos vectores velocidade \((\mathbf{v})\) e campo magnético \((\mathbf{B})\) sendo o seu sentido dado pela regra da mão direita para o produto externo de vectores.<br />
<br />
Quando a velocidade da carga e o campo magnético são mutuamente perpendiculares, a força magnética comporta-se como uma [https://pt.wikipedia.org/wiki/For%C3%A7a_centr%C3%ADpeta força centrípeta] e a carga descreve uma trajectória circular (Fig. 7}) cujo raio se pode calcular igualando os módulos das duas forças \((|\mathbf{F_c}|=|\mathbf{F_m})|\):<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>m\frac{v^2}{R}=qvB \rightarrow R=\frac{mv}{|q|B}</math>|| \(\quad\quad (13)\)<br />
|}<br />
<br />
Um caso particularmente interessante da força de Lorentz verifica-se quando a velocidade da carga é perpendicular tanto ao campo eléctrico como ao magnético. Nesse caso, as duas forças têm a mesma direcção. Adotando uma configuração como a representada na Fig. 8, as forças eléctrica e magnética têm sentidos opostos e podem compensar-se, anulando-se, o que permite que a carga mantenha uma trajectória rectilínea.<br />
<br />
Nesta repetição da experiência de Thomson iremos utilizar estes dois princípios para determinar a razão \(q/m\): <br />
* No primeiro conjunto de medidas, iremos determinar o raio da trajectória de um feixe de raios catódicos na presença de um campo magnético;<br />
* No segundo conjunto de medidas iremos equilibrar as forças de um campo magnético e um eléctrico de modo a que o feixe tenha uma forma aproximadamente rectilínea.<br />
<br />
=Figuras dos aparelhos da montagem experimental=<br />
<br />
{| class="wikitable" style="text-align: center;"<br />
|[[file:fig3-ThomsomEquip.jpg|thumb|center|upright=0.63]]||[[file:fig4-Thomson_Electron-Deflection-Tube-D.jpg|thumb|center|upright=0.75]]<br />
|-<br />
| Fig. 9 - Montagem da Experiência de Thomson com tubo de raios catódicos, suporte e par de bobinas de Helmholtz || Fig. 10 - Trajectória dos electrões sujeitos a um campo magnético perpendicular<br />
|}<br />
<br />
=Procedimento Experimental=<br />
==Material==<br />
<br />
[[file:fig5-TuboTL.jpg|thumb|upright=1.5 |alt=Diagrama do tubo utilizado e geometria das bobinas de Helmholtz. Esquerda: vista lateral, com ligações eléctricas do filamento e da tensão de aceleração. Direita: vista frontal, com ligações das bobinas de Helmholtz. |Fig. 11 - Diagrama do tubo utilizado e geometria das bobinas de Helmholtz. Esquerda: vista lateral, com ligações eléctricas do filamento e da tensão de aceleração. Direita: vista frontal, com ligações das bobinas de Helmholtz.]]<br />
<br />
# Ampola (tubo) de raios catódicos (TRC), [https://www.3bscientific.com/pt/tubo-de-desvio-de-eletrons-d-1000651-u19155-3b-scientific-teltron,p_1003_1349.html modelo TEL 525].<br />
# Fonte de alimentação do TRC, que inclui alimentação de alta tensão contínua (até 5000 V) aplicada aos eléctrodos (cátodo e ânodo) do TRC e alimentação de baixa tensão (6.3 V AC) para o filamento do TRC.<br />
# Par de bobinas que envolvem a parte esférica do TRC na configuração de Helmholtz (para criar um campo magnético aproximadamente homogéneo na região central entre as bobinas, de raio médio\(r\) e afastadas de \(r\)uma da outra).<br />
# Fonte de alimentação de corrente '''contínua''' (em modo DC) para as bobinas.<br />
# Multímetro (como amperímetro) a instalar em '''série''' no circuito das bobinas.<br />
<br />
O tubo TRC tem um filamento alimentado por 6.3 V (em modo AC). Este filamento emite electrões por efeito termiónico. <br />
Entre o ânodo e o cátodo do tubo estabelecem-se diferenças de potencial \( (V_+ - V_-) = U_a\). Os electrões são acelerados entre o cátodo e o ânodo e a sua velocidade à saída do ânodo é função de \(U_a\). <br />
<br />
Ao entrarem na parte esférica do tubo, os electrões podem ser deflectidos por ''campos magnéticos'' provocados por correntes que percorrem as bobinas de Helmholtz e/ou por ''campos eléctricos'' devidos à aplicação de tensão entre duas placas paralelas ligadas aos pontos 1 e 2 do diagrama (ver figura).<br />
<br />
O campo de indução magnética \(B\) devido às bobinas de Helmholtz é aproximadamente uniforme na região central entre as bobinas, e para uma corrente \(I\) é dado por <ref>No sistema SI, a unidade de campo magnético é o Tesla (T), sendo <br />
1 T=1 Weber/m\(^2\).</ref>:<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>B = \left(\frac{4}{5}\right)^{3/2} \cdot \frac{\mu_0 n I}{r} = \frac{32 \pi n }{5 \sqrt{5}} \cdot \frac{I}{r} \cdot 10^{-7}\textrm{ Weber/m}^{2}</math>|| \(\quad\quad (14)\)<br />
|}<br />
onde \(n = 320\) espiras, \(r= 0.068\) m e \(r = d/2\). Note que este valor \(d\) se refere ao ''diâmetro'' das bobinas (ver Fig. 11) e não à distância entre as placas da aâmpola.<br />
<br />
{|class="wikitable" style="background-color:#ffcccc;"<br />
| [[file:Electrocution-Safety.png|thumb|upright=0.5]] || '''Atenção:''' Este trabalho envolve o uso de fontes de alta tensão (até 5 kV) e correntes eléctricas elevadas (até 1 A). Assegure-se de que cumpre rigorosamente as medidas de segurança com equipamentos eléctricos, em particular:<br />
* Compreenda os [https://pt.wikipedia.org/wiki/Choque_el%C3%A9trico riscos inerentes] a tensões e correntes elevadas<br />
* Não pegue nos cabos ou conectores pela partes condutoras, apenas pelas partes isoladas<br />
* Assegure-se de que as fontes de tensão e corrente estão dsligadas antes de efectuar qualquer alteração nas montagens eléctricas<br />
* Em caso de dúvida, chame o docente<br />
|}<br />
<br />
==Determinação de \(q/m\) por deflexão magnética==<br />
===Trajectórias de partículas carregadas sujeitas a um campo magnético constante===<br />
Quando se aplica uma tensão \(U_a\)entre o ânodo e o cátodo (sem aplicar tensão entre os pontos 1 e 2 representados na figura acima), pode admitir-se que a velocidade final \(v\) dos electrões ao abandonarem o ânodo é dada pela seguinte expressão <br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>q\, U_a = \frac{1}{2} m \, v^2</math>|| \(\quad\quad (15)\)<br />
|}<br />
em que \(q\) é a carga do electrão e\(m\)a sua massa.<br />
<br />
Os electrões entram, com velocidade horizontal, na parte esférica do tubo, onde são deflectidos pelo campo magnético \(\mathbf{B}\) (com \(\mathbf{B}\perp\mathbf{v})\). A sua trajectória passa então a ser circular, com raio \(R\) verificando-se:<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>B \, q\, v = \frac{m\,v^2}{R} </math>|| \(\quad\quad (16)\)<br />
|}<br />
As trajectórias dos electrões podem ser visualizadas numa escala graduada feita de material fluorescente. A origem do reticulado está situada aproximadamente no início da zona sujeita ao campo \(\mathbf{B}\). Combinando (15) e (16) obtém-se uma expressão para a relação \(q/m\):<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>\frac{q}{m} = \frac{2\, U_a}{B^2\,R^2} </math>|| \(\quad\quad (17)\)<br />
|}<br />
<br />
em que:<br />
*\(U_a\) – impõe-se e mede-se diretamente no voltímetro da fonte de tensão.<br />
*\(B\) – calcula-se, para uma dada corrente \(I\) a partir da expressão (14).<br />
*\(R\) – determina-se por leitura no écran fluorescente, das coordenadas de posição \(y\) (horizontal) e \(z\) (vertical) de pontos do feixe. Por construção do tubo verifica-se:<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>R = \frac{y^2 + z^2}{2 \, z} </math>|| \(\quad\quad (18)\)<br />
|}<br />
<br />
===Modo de proceder===<br />
<br />
# Montar os circuitos eléctricos de acordo com a Fig. 11 (Secção [[Experiência_de_Thomson#Material|Material]]). Note que as ligações das bobinas devem garantir que a corrente eléctrica é percorrida no mesmo sentido, em ambas: para isso, deve usar os conectores na ordem \(A\rightarrow Z\) numa bobina e na ordem inversa na outra bobina. Chamar o docente para verificação, '''antes de ligar os aparelhos'''.<br />
# Verifique qual é o valor máximo da tensão disponível na fonte de alta tensão. Escolha um valor ligeiramente inferior.<br />
# Ajustar a corrente das bobinas de Helmholtz \(I_+\) de modo a que a circunferência passe por um ponto bem determinado. <ref>Utilize de preferência os maiores valores possíveis para o raio \(R\) de forma a que o feixe se encontre na zona central entre as bobines.</ref> Calcule \(R\). Inverta o sentido da corrente e determine um novo \(I_-\) para o mesmo raio \(R\). Tomando \(I_{\textrm{medio}} = (I_+ + I_-)/2\), calcule o campo magnético \(B_{\textrm{medio}}\). Utilize a semi-diferença, \((I_+ - I_-)/2\) para a estimativa das incertezas \(\delta I_{\textrm{medio}}\) e \(\delta B_{\textrm{medio}}\).<br />
# Repita o ponto 2) para quatro novos valores de\(R\). <br />
# Repetir 1), 2) e 3) e para os mesmos \(R\) para dois valores inferiores de tensão, afastados por exemplo de 500 V entre si.<br />
# Apresente os valores de \(q/m\) para os 15 pares de determinações. Calcule a média desses valores, assim como a incerteza da média.<br />
# Para um dos pares de pontos, estime a contribuição relativa das incertezas das grandezas que mediu para a incerteza total. Compare este erro assim calculado com a incerteza calculada a partir dos 15 valores calculados. Apresente para cada raio o valor de \(q/m\) assim como o erro associado a cada uma das determinações. Compare e comente os resultados.<br />
# Apresente um valor final para \(q/m\), tendo em conta que se trata de uma ''combinação de resultados'' (e não uma média simples). Estime a precisão e a exatidão obtida nas determinações que realizou.<br />
<br />
==Determinação de \(q/m\) por deflexão magnética e eléctrica quase compensada==<br />
<br />
===Situação de equilíbrio entre as interacções eléctrica e magnética===<br />
<br />
Se, na força de Lorentz, os dois termos se equilibrarem — ou seja, se as forças electrostática e magnética forem de igual módulo e de sentidos opostos — a carga \(q\) não é desviada da sua trajectória. No nosso caso, em que \(\mathbf{B} \perp \mathbf{v}\), a condição de equilíbrio é dada por <math> |\mathbf{E}| = v\, |\mathbf{B}|</math>.<br />
<br />
===Montagem a efectuar===<br />
<br />
[[file:fig6-TuboTLE.jpg|thumb|upright=1.0 |alt=Deflexão magnética e eléctrica quase compensada: ligações eléctricas do filamento, da tensão de aceleração e das placas. |Fig. 12 - Deflexão magnética e eléctrica quase compensada: ligações eléctricas do filamento, da tensão de aceleração e das placas.]]<br />
<br />
Aproveitando a montagem já efectuada no ponto anterior, ligue agora os terminais no topo e na base da âmpola (ver figura) à fonte de alta tensão que gera a tensão \(U_a\) produzindo assim na região do écran fluorescente um campo eléctrico. Fazendo com que as bobinas sejam percorridas por uma corrente com intensidade e "sentido" convenientes, podemos obter uma força de origem magnética anti-paralela à provocada pelo campo \(\mathbf{E}\). Deste modo, a trajectória visualizada no écran será aproximadamente retilínea, sendo a condição de equilíbrio dada por:<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math> |\vec{E}| = v\, |\vec{B}| = \frac{U_a}{d}</math>|| \(\quad\quad (19)\)<br />
|}<br />
onde \(d\) é a distância entre as placas do écran fluorescente e \(U_a\) a tensão entre as mesmas, que é como se disse igual à tensão de aceleração. A equação acima permite-nos calcular a velocidade dos electrões, uma vez que podemos conhecer os valores de todas as outras variáveis aí intervenientes. O conhecimento de \(v\) permite-nos calcular \(q/m\) tendo em conta que, segundo <math>qU_a=mv^2/2</math>, deverá ser:<br />
<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>\frac{q}{m} = \frac{v^2}{2} \; \frac{1}{U_a}<br />
</math>|| \(\quad\quad (20)\)<br />
|}<br />
<br />
Eliminando o termo <math>v</math> obtemos finalmente:<br />
{| border="0" cellpadding="5" cellspacing="0" align="center"<br />
! style="background:#efefef;" |<math>\frac{q}{m} = \frac{1}{2} \; \frac{U_a}{B^2d^2}<br />
</math>|| \(\quad\quad (21)\)<br />
|}<br />
<br />
===Modo de proceder===<br />
<br />
# Para cada uma das quatro tensões de trabalho \(U_a\)já referidas, aplicadas agora também às placas que produzem o campo eléctrico, determine o valor de \(B\) (a partir de \(I\) que conduz ao anulamento das forças de origem eléctrica e magnética.<br />
# Inverta o sentido dos campos eléctricos e magnéticos e repita a determinação do valor de \(B\).<br />
# Apresente os valores de \(q/m\). Analise as diferentes contribuições para a incerteza total. Estime o valor da relação carga/massa do electrão, assim como a precisão e a exatidão obtida nas determinações que realizou.<br />
# Observe a trajectória quando as forças de origem eléctrica e magnética não se compensam. Comente.<br />
<br />
=Notas=<br />
<references /><br />
<br />
=Ligações externas=<br />
* [https://www.youtube.com/watch?v=5YYVnHN7xwM Charge to mass ratio of an electron] Animação da experiência de Thomson<br />
* [https://www.youtube.com/watch?v=ZxtPGN8Ipa0 Motion of electric charges in a uniform magnetic field] Animação do movimento de cargas em campos magnéticos uniformes<br />
* [https://www.youtube.com/watch?v=q4Hjqvyv-Ek Deflection of an electron beam in a magnetic field] Deflexão de um feixe de raios catódicos num campo magnético</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=%C3%93ptica_Geom%C3%A9trica&diff=6081Óptica Geométrica2025-03-18T14:55:44Z<p>Ist23437: /* Polarização da luz. Ângulo de Brewster */</p>
<hr />
<div><big>Construções geométricas em lentes delgadas</big><br />
<br />
{|class="wikitable" style="background-color:#ccddff;"<br />
| Não consegue ver as equações correctamente? Mude https para http no endereço desta página e recarregue.<br />
|}<br />
<br />
=Objectivos do trabalho=<br />
<br />
Pretende-se estudar vários aspectos da luz do ponto de vista da [https://pt.wikipedia.org/wiki/%C3%93ptica_geom%C3%A9trica óptica geométrica], tais como a [https://pt.wikipedia.org/wiki/Reflex%C3%A3o_(f%C3%ADsica) reflexão] e [https://pt.wikipedia.org/wiki/Refra%C3%A7%C3%A3o refracção] entre meios, a [https://pt.wikipedia.org/wiki/Polariza%C3%A7%C3%A3o_eletromagn%C3%A9tica polarização], [https://pt.wikipedia.org/wiki/Lente lentes delgadas] e associações de lentes. Iremos estudar a formação de imagens reais e virtuais, verificar como estas dependem das distâncias envolvidas no sistema óptico, e testar um microscópio composto.<br />
<br />
=Conceitos fundamentais=<br />
==Traçado de raios==<br />
A óptica geométrica, ou óptica de raios, é uma abordagem que consiste em descrever a propagação da luz através de raios. Um raio é um modelo simplificado, na forma de uma linha, que descreve o caminho percorrido pela luz entre duas superfícies. Para descrever a propagação de um feixe de luz através de um sistema, utilizamos um conjunto de raios, que se propagam utilizando o método do [https://pt.wikipedia.org/wiki/Ray_tracing_(f%C3%ADsica) traçado de raios].<br />
Este método é suficiente para explicar fenómenos como a reflexão e a refracção da luz e é particularmente útil na descrição de sistemas e instrumentos ópticos, sendo válida desde que as dimensões dos objectos envolvidos sejam muito maiores que o [https://pt.wikipedia.org/wiki/Comprimento_de_onda comprimento de onda] da luz visível (\(\sim\)0,4 \(\mu\)m a 0,7 \(\mu\)m).<br />
<br />
O comportamento dos raios obedece a algumas regras simples:<br />
[[file:OG-snell.png|thumb|upright=0.5 |Raio reflectido e refractado na fronteira entre dois meios. |Fig. 1 - Raio reflectido e refractado na fronteira entre dois meios.]]<br />
{| class="wikitable"<br />
|<br />
# Num meio uniforme, como o ar ou um vidro, um raio é uma linha recta;<br />
# Um meio óptico é definido por uma grandeza \(n\geq1\), chamada índice de refracção;<br />
# Na fronteira entre dois meios, um raio é reflectido e/ou refractado, verificando-se (ver Fig. 1):<br />
#* o ângulo de reflexão é igual ao ângulo de incidência<br />
#* o ângulo de refracção \(\theta_r\) e o ângulo de incidência \(\theta_i\) (medidos relativamente à normal à superfície) obedecem à [https://pt.wikipedia.org/wiki/Lei_de_Snell Lei de Snell-Descartes], em que \(n_i\)e \(n_r\)são respectivamente os índices de refracção do meio de incidência e do meio de refracção: <br />
<center>\(n_i\sin{\theta_i}=n_r\sin{\theta_r}\)</center><br />
|}<br />
<br />
[[file:OG-brewster.png|thumb|upright=0.5 |Fig. 2 - Reflectividade vs. ângulo de incidência e direcção de polarização (esq.) e geometria para ângulo de Brewster (dir.).]]<br />
<br />
[[file:OG-pol-luz.png|thumb|upright=0.5 |Fig. 3(a) - Obtenção de luz polarizada através de um filtro polarizador.]]<br />
<br />
[[file:Polarizadores.png|thumb|upright=0.5 |Fig. 3(b) - Efeito de dois polarizadores colocados em cima de um écrã de computador.]]<br />
==Reflexão, refracção e polarização==<br />
<br />
A eficiência com que um feixe luminoso é reflectido ou refractado numa fronteira entre dois meios de índices de refracção \(n_1\)e \(n_2\) depende, entre outros, do ângulo de incidência e da polarização da luz. A Fig. 2 mostra como varia a reflectividade de uma superfície de vidro em função do ângulo de incidência, para polarizações horizontal e vertical (admitindo que o plano de incidência e reflexão é horizontal). Para um ângulo específico, designado [https://pt.wikipedia.org/wiki/%C3%82ngulo_de_Brewster ângulo de Brewster] e dado por \(\theta_B=\arctan(n_2/n_1)\), a componente horizontal da polarização não é reflectida, pelo que a luz reflectida fica com polarização vertical. Esta é uma forma de criar luz polarizada a partir de uma fonte não-polarizada. A figura ilustra também a geometria dos raios luminosos numa separação entre dois meios, no caso de incidência em ângulo de Brewster. Como se pode apreciar, nessa configuração o raio reflectido e o raio refractado fazem entre si um ângulo de 90\(^\circ\).<br />
<br />
Pode-se polarizar a luz emitida por uma fonte não-polarizada através de um simples [https://pt.wikipedia.org/wiki/Filtro_polarizador filtro polarizador] (ou ''polaroide''). Orientando o ângulo do filtro relativamente à direcção dos raios luminosos, é possível definir a direcção de polarização. Por exemplo, no caso da Fig. 3(a) a luz obtida é polarizada verticalmente.<br />
<br />
Quando se coloca um polarizador no caminho de luz já polarizada, a intensidade da luz que passa depende do ângulo entre o ''eixo do polarizador'' e a direcção de polarização da luz. A Fig. 3(b) mostra o efeito de dois polarizadores colocados em cima do écrã de um computador (o fundo branco da imagem). Normalmente, por uma questão de melhorar a visibilidade, os écrans de computador de tipo LCD ou OLED emitem luz polarizada verticalmente. Assim, quando o eixo do polarizador (direcção 0\(^\circ\)-180\(^\circ\)) também está vertical (esquerda), a quantidade de luz transmitida é máxima. Quando esse eixo está na horizontal (direita), a quantidade de luz transmitida é mínima.<br />
<br />
= Construções geométricas em lentes delgadas=<br />
<br />
Para garantir que compreende adequadamente as secções seguintes, leia antes o documento de apoio [[Óptica geométrica e lentes]].<br />
<br />
=Instrumentos ópticos=<br />
Um instrumento óptico é um dispositivo baseado nos princípios da óptica cujo objectivo é auxiliar a visão humana. Nestes sistemas, designamos por ''objectiva'' a lente que está do lado do objeto AB e por ''ocular'' aquela que está do lado do observador, com distâncias focais \(f_{obj}\) e \(f_{ocu}\) respetivamente. Em ambos os casos, a ocular está próxima da ''imagem intermédia'' A'B' formada pela objectiva. Sendo a distância inferior à distância focal \(f_{ocu}\), a imagem final será ''virtual'', ou seja, visível apenas através da lente.<br />
Assim, o papel da ocular consiste em ampliar a imagem intermédia, tal como uma lupa amplia um objeto.<br />
<br />
==O olho humano==<br />
Vamos primeiro abordar a fisiologia do olho humano (Fig. 17) para compreender as suas limitações. Este pode ser considerado como um sistema óptico que projecta imagens (reais) dos objectos exteriores na retina, através de duas lentes convergentes: a córnea e o cristalino. Para o nosso estudo, vamos considerar que estas lentes são substituídas por um sistema equivalente constituído por uma única lente, com o máximo de distância focal \(f\) igual a 2,5 cm, que é a média da distância entre a córnea e a retina. A potência em dioptrias (dt) desta lente equivalente é dada por:<br />
<br />
<math display=“block”><br />
D=\frac{1}{f} \,[\mathrm{m}^{-1}] = \frac{1}{0,025} \,[\mathrm{m}^{-1}] = 40 \,[\mathrm{m}^{-1}]=40\, \mathrm{dt}.<br />
</math><br />
<br />
[[file:OG-olho-1.png|thumb|upright=0.5 |Fig. 17 - Diagrama dos principais elementos do olho humano.]]<br />
<br />
Para uma pessoa com visão normal ou munida de correção adequada (óculos graduados ou lentes de contacto), os raios ópticos provenientes de um objecto no infinito<ref>Para efeitos práticos, considera-se o infinito óptico qualquer distância superior a 5 m.</ref> chegam paralelos ao olho e são focados na retina sem necessidade de esforço, ou seja, com o olho relaxado (Fig. 18 à esq.). À medida que o objecto se aproxima do olho, é necessário os músculos ciliares aumentarem a curvatura da lente para criar uma imagem focada na retina - a isto chama-se ''acomodação do olho''. O ponto mais próximo do olho para o qual a lente ainda consegue focar a imagem na retina é designado por ''ponto próximo'' (Fig. 18 à dir.) e considera-se igual a 0,25 m para uma visão normal padrão, valor que tem tendência a aumentar com a idade.<br />
<br />
[[file:OG-olho-2.png|thumb|upright=1.0 |Fig. 18 - Esquema do olho no caso de objectos no infinito (esq.) e no ponto próximo (dir.).]]<br />
<br />
O tamanho aparente dum objecto é determinado pelo tamanho que a imagem apresenta na retina. Mesmo sem variar o tamanho real do objecto, este pode ser visto maior se o aproximarmos do olho, porque o tamanho da sua imagem na retina é maior. A avaliação do tamanho da imagem na retina pode ser feita através da medição do ângulo \(\theta\), que corresponde à inclinação dos raios principais do extremo da imagem (Fig. 19).<br />
<br />
[[file:OG-olho-3.png|thumb|upright=1.0 |Fig. 19 - Formação de imagem na retina de um objecto de altura \(h\)a uma distância \(s\).]]<br />
<br />
Considere-se um objecto com altura \(h\) a uma distância \(s\) do olho. Para o objeto podemos escrever \(\tan\theta=h/s\). Para a imagem na retina, de altura \(y'\), vem \(\tan\theta = y'/\)(2,5 cm). Na aproximação paraxial, ou seja de ângulos pequenos, podemos usar \(\tan\theta \approx\theta\), e assim \(\theta\approx h/s=y'/\)(2,5 cm). Desta relação conclui-se que \(y'\) é proporcional a \(h\), tamanho do objecto, e inversamente proporcional à distância \(s\) entre o objecto e o olho. <br />
<br />
O princípio dos instrumentos ópticos consiste no aumento do tamanho da imagem na retina, \(y'\), permitindo assim visualizar objectos muito pequenos ou afastados. Do exposto acima, podemos concluir que a sua operação baseia-se na criação de uma imagem (real ou virtual) com um tamanho aparente maior que \(h\) e/ou a uma distância aparente inferior a \(s\). Em qualquer dos casos, a imagem final produzida deverá estar situada além do ponto próximo, caso contrário não conseguirá ser focada.<br />
<br />
==Lupa==<br />
[[file:OG-olho-4.png|thumb|upright=1.0 |Fig. 20 - Objecto no ponto próximo visto pelo olho desarmado.]]<br />
A [https://pt.wikipedia.org/wiki/Lupa lupa simples] é o instrumento óptico mais elementar. Consiste numa só lente convergente e permite aumentar o tamanho aparente do objecto, ou seja, o tamanho da imagem na retina. Sabendo que a maior imagem que se pode obter dum objecto com o olho desarmado é quando o objecto está no ponto próximo (Fig. 20), e dado que \(y'_0\), tamanho da imagem na retina, é proporcional ao ângulo definido entre a altura do objecto \(h_0\)e a sua distância ao olho, pode-se escrever a relação<br />
<br />
<math display=“block”><br />
\theta_0=h_0/0,25<br />
</math><br />
<br />
Na visão auxiliada pela lupa, esta é colocada perto do olho, e o objecto colocado a uma distância inferior ao foco. A imagem produzida pela lupa é virtual, ampliada e direita.<br />
<br />
== Ampliação angular==<br />
[[file:OG-olho-5.png|thumb|upright=1.0 |Fig. 21 - Formação de imagem com o auxílio de uma lupa a uma distância \(b\)do olho. O objecto \(h_0\)está a uma distância \(d_O<f\)da lente, e a imagem (virtual) \(h'_a\)aparenta estar a uma distância \(d_i\)da lente e \(L\)do olho.]]<br />
A ''ampliação angular'' \(M_A\) dum instrumento óptico é determinada pela razão entre \(y'_a\), dimensão da imagem na retina quando o objecto é visto através do instrumento (Fig. 21), e \(y'_0\), dimensão da imagem na retina quando vista pelo olho desarmado e o objecto no ponto próximo. A razão entre os respectivos ângulos permite esse cálculo, isto é <br />
<br />
<math display=“block”><br />
M_A=\frac{y'_a}{y'_0}=\frac{\theta_a}{\theta_0}<br />
</math><br />
<br />
Tirando partido da aproximação paraxial, temos \(\tan\theta_a = h'_a / L \approx \theta_a\) e \(\tan\theta_0 = h_0 / 0,25 \approx\theta_0\), portanto pode-se escrever a ampliação angular como:<br />
<br />
<math display=“block”><br />
M_A = \frac{h'_a/L}{h_0/0,25}=-\frac{d_i\,0,25}{d_0 L}= \frac{0,25}{L}\left(1-\frac{d_i}{f}\right) <br />
</math><br />
<br />
onde na última igualdade se recorreu à equação dos focos conjugados. Como a distância à imagem é negativa, \(d_i = - (L – b)\), obtém-se por fim<br />
<br />
{| class="wikitable"<br />
| <math display=“block”><br />
M_A = \frac{0,25}{L}\left(1+\frac{L–b}{f}\right)<br />
</math><br />
|}<br />
<br />
<br />
Da análise desta expressão pode-se dizer que a ampliação diminui se \(L\) ou \(b\) aumentam. Existem três casos particulares de ampliação:<br />
<br />
{| class="wikitable"<br />
|-<br />
! Caso !! Ampliação angular !! Interpretação<br />
|-<br />
| \(b=f\) || <center>\(M_A = \frac{0,25}{f}=0,25D\)</center> || O olho está à distância focal da lupa. \(D\) é a potência da lupa em dioptrias.<br />
|-<br />
| \(b=0\) || <center>\(M_A = 0,25\left(\frac{1}{L}+\frac{1}{f}\right)\)</center> || O olho está encostado à lupa. Se \(b=0\) e também \(L = 0,25\) m (valor mínimo para \(L\), uma vez que a imagem também deve poder ser focada correctamente pelo olho), então obtém-se para \(M_A\) o valor máximo, igual a \(M_A = 1+\frac{0,25}{f}= 1+0,25D\). Neste caso, a imagem aumentada surge à distância do ponto próximo.<br />
|-<br />
| \(d_O=f\) || <center>\(M_A = \lim_{L\to\infty}\frac{0,25}{L}\left(1+\frac{L–b}{f}\right)\)\(= \frac{0,25}{f}=0,25D\)</center> || O objecto é colocado no foco e a lupa forma a sua imagem no infinito \((L = \infty)\). Neste caso, o olho recebe raios paralelos e não necessita de fazer acomodação, o que é mais cómodo, e a ampliação apenas se reduz de uma unidade relativamente ao caso anterior.<br />
''Exemplo'': uma lente com \(D=10\) dioptrias tem uma distância focal \(f=10\) cm, e para \(L=\infty\) tem uma ampliação angular de \(M_A=\)2,5 vezes.<br />
|}<br />
<br />
==Microscópio composto==<br />
<br />
O [https://pt.wikipedia.org/wiki/Microsc%C3%B3pio_%C3%B3ptico microscópio] é o instrumento óptico empregado para observar objectos pequenos, colocados muito próximos do instrumento. Na sua forma mais simples, consiste em duas lentes convergentes. A lente mais próxima do objecto ([https://pt.wikipedia.org/wiki/Objetiva_(fotografia) objectiva]) tem uma distância focal \(f_{obj}\), menor que a distância focal \(f_{ocu}\) da lente mais perto do olho ([https://pt.wikipedia.org/wiki/Ocular ocular]) (Fig. 22).<br />
<br />
[[file:OG-microscopio.png|thumb|upright=1.0 |Fig. 22 - Formação de imagem num microscópio.]]<br />
<br />
Um objecto de altura \(h\) é colocado, em relação à objectiva, mais afastado do que o foco desta, produzindo uma imagem de tamanho \(h'\) que é real, invertida e maior que o objecto. A objectiva produz assim uma imagem com ''ampliação transversal linear'' \(M_T\),<ref>Conforme vimos atrás, para o caso de uma única lente esta ampliação é designada \(A\).</ref> dada por:<br />
<br />
<math display=“block”><br />
M_T=\frac{h'}{h} = -\frac{L\tan\theta}{f_{obj}\tan\theta}= -\frac{L}{f_{obj}}<br />
</math><br />
<br />
O sinal negativo indica que a imagem é invertida e, uma vez que é real, a imagem pode ser projectada sobre um alvo para se medir o seu tamanho.<br />
<br />
A lente ocular é usada para aumentar a imagem formada pela lente objectiva. Assim, a ocular é colocada de modo a que a imagem \(h'\) produzida pela objectiva (agora ''objecto virtual'' da segunda lente) venha localizar-se a uma distância ligeiramente inferior ao seu foco \(f_{ocu}\). Nesta condição, a ocular actua como uma simples lupa, que permite trazer o objecto \(h’\) para uma distância mais curta do que o ponto próximo (0,25 m), e produz a imagem \(h"\). A ''ampliação final'' \(M\) é dada pelo produto da ampliação transversal para a lente objectiva e a ampliação angular \(M_A\) obtida para a lente ocular. No caso da lente ocular estar encostada ao olho, como é habitual num microscópio, estamos no caso \(b=0\) e, das expressões anteriores para a ampliação linear e angular, obtemos<br />
<br />
<math display=“block”><br />
M = \frac{h''}{h}=M_T\times M_A<br />
</math><br />
<br />
=Procedimento experimental=<br />
==Material==<br />
Caixa de óptica equipada com<br />
* calha graduada<br />
* fonte luminosa com lâmpada de incandescência linear<br />
* lentes convergentes e divergente<br />
* semi-cilindro de vidro acrílico<br />
* diafragmas de fendas lineares (fenda única e fendas múltiplas)<br />
* polaroides<br />
* suportes<br />
<br />
==Trabalho preparatório==<br />
# Preencha os objectivos do trabalho que irá realizar na sessão de laboratório. <br />
# Preencha o quadro com as equações necessárias para o cálculo das grandezas, bem como as suas incertezas. <br />
<br />
<br />
== Determinação do índice de refracção dum vidro acrílico==<br />
===Alinhamento===<br />
O alinhamento prévio é essencial para assegurar que as medições são efetuadas correctamente.<br />
[[file:feixe-colimado.jpg|thumb|upright=1.0 |Fig. 23 - Ilustração do método de colimação do feixe.]]<br />
# Monte a fonte luminosa numa das extremidades da calha graduada e ligue a lâmpada.<br />
# Utilizando a lente cilíndrica, obtenha um feixe de luz ''colimado'', isto é de raios paralelos. A Fig. 23 ilustra o posicionamento da lente e o resultado pretendido. À distância correcta, o feixe de luz tem uma largura aproximadamente constante.<br />
# Sobreponha os dois diafragmas num único suporte, de modo a obter uma linha vertical de luz, estreita (\(\approx\)1 mm), alinhada com o eixo da calha graduada. Verifique que a espessura do feixe de luz se mantém tão constante quanto possível ao longo de toda a calha. Antes de começar o passo seguinte, chame o docente para validar o alinhamento.<br />
<br />
===Face plana===<br />
# <li value="4">Monte o suporte com o círculo graduado, de modo a que o feixe de luz branca incida na sua superfície plana e atravesse as posições 0 e 180 graus. Ajuste o alinhamento das fendas, se necessário.<br />
# Coloque o semi-cilindro de vidro acrílico em cima do suporte, de modo a que a superfície plana fique alinhada com o centro e virada para o feixe.<br />
# Observe e obtenha os ângulos de reflexão e de transmissão para vários valores dos ângulos do feixe incidente, à esquerda e à direita. Registe medições para, pelo menos, nove valores diferentes do ângulo de incidência.</li><br />
# Represente as medições num gráfico e, a partir deste, determine por ajuste o índice de refracção do vidro acrílico. Anexe o gráfico ao relatório.<br />
<br />
===Face cilíndrica===<br />
# <li value="8">Rode o círculo graduado de modo a que o feixe de luz incida na superfície cilíndrica do vidro acrílico. Repita as medidas e a análise dos resultados.<br />
<br />
===Ângulo-limite===<br />
# <li value="9">Estime o valor do índice de refracção a partir do ângulo limite de reflexão total. <br />
# Para o desvio à exatidão, considere exato o valor médio das medições anteriores. <br />
# Nas suas conclusões, compare os valores obtidos para \(n_{vidro}\) e a sua precisão<br />
<br />
==Polarização da luz. Ângulo de Brewster==<br />
# Usando a mesma montagem do ponto anterior para incidência na face plana, polarize o feixe perpendicularmente ao plano de incidência, orientando o eixo \(0^\circ-180^\circ\) do filtro polarizador na horizontal e colocando-o antes da plataforma. Deste modo, para o ângulo de Brewster a luz reflectida pelo semi-cilindro irá anular-se.<br />
# A partir do valor médio obtido para o índice de refracção (o que usou na secção anterior), calcule o valor "teórico" do ângulo de Brewster e verifique experimentalmente que, para esse valor, os raios reflectido e transmitido fazem 90\(^\circ\) entre si. <br />
# Para ângulos de incidência próximos do ângulo de Brewster, obtenha o intervalo angular em que praticamente se extingue o feixe reflectido.<br />
<br />
==Distância focal de uma lente convergente ( \(f \approx\)75 mm)==<br />
# Obtenha um feixe de luz branca de raios paralelos, usando a lente colimadora.<br />
# Seleccione a lente de distância focal mais curta e determine o seu valor pelo método directo. Repita a experiência duas vezes, colocando a lente noutra posição relativamente à lente de raios paralelos. <br />
# Retire a lente colimadora e coloque o objecto com mira no suporte da calha, iluminando-o directamente com a fonte luminosa. Coloque a mesma lente convergente a uma distância 150 mm \(> d_O >\)75 mm do objeto.<br />
# Com o écran plano, procure a posição correcta para obter uma imagem focada. Utilizando a equação dos focos conjugados, calcule de novo a d.f. da lente. <br />
# Na folha quadriculada em anexo, desenhe um diagrama com o eixo óptico, o objecto e a lente convergente. Utilizando as aproximações paraxial e das lentes delgadas, desenhe a construção geométrica e obtenha a posição da imagem e a respectiva ampliação.<br />
# Medindo agora a imagem, determine a ampliação linear. Compare-a com a que podia calcular pelas distância \(d_O\) e \(d_I\). <br />
# Repita a experiência, colocando a lente noutra posição relativamente ao objecto. <br />
# Compare o valor da distância focal com o obtido em (1) e estime a precisão envolvida em cada um dos métodos que utilizou.<br />
<br />
== Distância focal de uma lente divergente (\(f \approx -\)150 mm)==<br />
# Associe no mesmo suporte a lente divergente com uma convergente (\(f \approx\)75 mm), de forma a que o par se comporte como um sistema convergente (com \(D\approx 10\)mm). Escolha uma distância ao objecto \(D_O\)adequada e utilize esta montagem para determinar a distância focal da lente divergente.<br />
# Repita a montagem para uma diferente distância ao objecto.<br />
<br />
==Microscópio composto==<br />
<br />
===Material===<br />
* Lente objectiva \(f\)= 75 mm<br />
* Lente ocular \(f\)= 150 mm<br />
* Écrã graduado (escala de referência)<br />
* Écrã transparente graduado (objecto)<br />
<br />
===Medição da ampliação angular da ocular===<br />
Para esta medição vamos usar a lente ocular como uma lupa (ver Fig. 21). Os passos seguintes permitem determinar a ampliação de um objecto, visualizado através da lupa, em relação a uma escala de referência. Para esta determinação, iremos sobrepor visualmente o objecto (observado com o olho esquerdo) e a escala (observada com o olho direito) e fazer uma comparação directa dos seus tamanhos relativos.<br />
# Retire todos os componentes da calha. Coloque um suporte a \(d_i\approx 25\) cm da extremidade da calha, de modo a ficar no ponto próximo do observador. Monte um ecrã graduado (E1) na parte lateral direita do suporte, deslocado em relação ao centro do mesmo (ver Fig. 24). Este ecrã será a ''escala de referência'' em relação à qual se vai medir a ampliação.<br />
# Monte a lente ocular junto à mesma extremidade da calha, de modo a obter a condição \(b\sim 0\) (Fig. 24). Calcule qual a distância \(d_O\) dessa lente a que deverá colocar o objecto de modo a que a sua imagem surja no ponto próximo. Use os valores de \(d_O\) e \(d_i\) para determinar a ampliação angular (calculada).<br />
# Coloque o ecrã transparente graduado (E2) entre a lente e E1, próximo da posição \(d_O\) calculada acima, de modo a conseguir visualizar simultaneamente (a) a escala de E2 através da lente, com o olho esquerdo, e (b) a escala de E1 com o olho direito (Fig. 24, imagem inserida)<br />
# Ajuste a posição de E2 até conseguir focar simultaneamente as imagens em ambos os olhos. Sobrepondo visualmente as duas escalas graduadas, escolha um comprimento \(h_O\) em E2, meça o tamanho aparente \(h'_a\) da sua imagem (virtual) em relação à escala e determine a ampliação angular \(M_A=h'_a/h_O\) da ocular.<br />
<br />
[[file:OG-micro-composto.png|thumb|upright=1.0 |Fig. 24 - Esquema para a medição da ampliação angular da ocular.]]<br />
<br />
===Medição da ampliação linear da objectiva===<br />
Para esta medição vamos usar a objectiva como um sistema de formação de imagem (real) a partir de um objecto.<br />
# <li value="5">Mantenha a ocular montada mas retire o suporte de E1.<br />
# Na extremidade oposta à da ocular, monte a fonte luminosa e coloque o objecto (écran E1) imediatamente encostado à saída da luz.<br />
# Usando como referência a Fig. 22, junte uma objectiva de modo a observar uma imagem do alvo no plano de E2. <br />
# Observe todo o sistema através da ocular. Ajuste a posição da objectiva para conseguir observar uma imagem focada.<br />
# Escolha uma altura \(h_O\) adequada do écran graduado. Observe a imagem intermédia \(h’\) no plano de E2 e meça a sua ampliação \(M_T=h'/h_O\).<br />
# Calcule a ampliação final do microscópio composto.<br />
<br />
=Notas=</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6080Laser Safety Manual2025-03-18T11:00:39Z<p>Ist23437: </p>
<hr />
<div>'''Latest revision: March 2025'''<br />
<br />
Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
! Laser class !! Description !! Safety measures<br />
|-<br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
|| No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
|| Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
|| Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
|| Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
|rowspan="3"| '''Class 3''' ||colspan="2"| May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
|-<br />
|'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers. || Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
|-<br />
|'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers. || Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
|| Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also the section [[http://www.mysolutions.tecnico.ulisboa.pt/wiki/index.php?title=Laser_Safety_Manual#L2I_floor_plan|L2I floor plan]] below for information about the location of each item.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE.<br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. The tables below detail the layout of each one, with the differential switches highlighted in blue.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board1.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
|bgcolor = "0088FF" | 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
|bgcolor = "0088FF" | 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 2'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board2.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=7 | Top<br />
| 1 || 40 || Differential switch for single phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets (Fastlite)<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| rowspan=3 | Middle<br />
| 8 || 40 || Differential switch for three-phase sockets<br />
|-<br />
| 9 || 16 || Three-phase socket B<br />
|-<br />
| 10 || 40 || Three-phase socket C<br />
|-<br />
| Bottom || 11 || 63 || Global panel circuit breaker<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 3'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board3.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=14 | Top<br />
| 1 || 16 || Single-phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| 8 || 16 || Single-phase sockets<br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || || <br />
|-<br />
| 11 || || <br />
|-<br />
| 12 || 10 || <br />
|-<br />
| 13 || 10 || <br />
|-<br />
|bgcolor = "0088FF" | 14 || 63 || <br />
|-<br />
| rowspan=7 | Middle<br />
| 15 || || Vacuum pump<br />
|-<br />
| 16 || || Overhead crane<br />
|-<br />
| 17 || || Three-phase socket<br />
|-<br />
|bgcolor = "0088FF" | 18 || 25 || Differential switch for circuit breakers 15-17 (?)<br />
|-<br />
| 19 || || Electrical panel 1<br />
|-<br />
| 20 || || Air Treatment Unit<br />
|-<br />
|bgcolor = "0088FF" | 21 || || <br />
|-<br />
| Bottom || || || Global panel switch<br />
<br />
|}<br />
<br />
==L2I floor plan==<br />
The figure below shows a schematic plan of L2I with items relevant to safety.<br /><br />
[[Ficheiro:L2I-Planta-legendas.png|500px|left|Flor plan of L2I.]]</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6079Laser Safety Manual2025-03-17T15:03:47Z<p>Ist23437: /* L2I floor plan */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
! Laser class !! Description !! Safety measures<br />
|-<br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
|| No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
|| Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
|| Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
|| Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
|rowspan="3"| '''Class 3''' ||colspan="2"| May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
|-<br />
|'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers. || Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
|-<br />
|'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers. || Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
|| Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also the section [[http://www.mysolutions.tecnico.ulisboa.pt/wiki/index.php?title=Laser_Safety_Manual#L2I_floor_plan|L2I floor plan]] below for information about the location of each item.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE.<br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. The tables below detail the layout of each one, with the differential switches highlighted in blue.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board1.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
|bgcolor = "0088FF" | 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
|bgcolor = "0088FF" | 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 2'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board2.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=7 | Top<br />
| 1 || 40 || Differential switch for single phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets (Fastlite)<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| rowspan=3 | Middle<br />
| 8 || 40 || Differential switch for three-phase sockets<br />
|-<br />
| 9 || 16 || Three-phase socket B<br />
|-<br />
| 10 || 40 || Three-phase socket C<br />
|-<br />
| Bottom || 11 || 63 || Global panel circuit breaker<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 3'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board3.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=14 | Top<br />
| 1 || 16 || Single-phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| 8 || 16 || Single-phase sockets<br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || || <br />
|-<br />
| 11 || || <br />
|-<br />
| 12 || 10 || <br />
|-<br />
| 13 || 10 || <br />
|-<br />
|bgcolor = "0088FF" | 14 || 63 || <br />
|-<br />
| rowspan=7 | Middle<br />
| 15 || || Vacuum pump<br />
|-<br />
| 16 || || Overhead crane<br />
|-<br />
| 17 || || Three-phase socket<br />
|-<br />
|bgcolor = "0088FF" | 18 || 25 || Differential switch for circuit breakers 15-17 (?)<br />
|-<br />
| 19 || || Electrical panel 1<br />
|-<br />
| 20 || || Air Treatment Unit<br />
|-<br />
|bgcolor = "0088FF" | 21 || || <br />
|-<br />
| Bottom || || || Global panel switch<br />
<br />
|}<br />
<br />
==L2I floor plan==<br />
The figure below shows a schematic plan of L2I with items relevant to safety.<br /><br />
[[Ficheiro:L2I-Planta-legendas.png|500px|left|Flor plan of L2I.]]</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6078Laser Safety Manual2025-03-17T15:03:28Z<p>Ist23437: /* L2I floor plan */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
! Laser class !! Description !! Safety measures<br />
|-<br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
|| No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
|| Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
|| Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
|| Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
|rowspan="3"| '''Class 3''' ||colspan="2"| May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
|-<br />
|'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers. || Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
|-<br />
|'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers. || Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
|| Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also the section [[http://www.mysolutions.tecnico.ulisboa.pt/wiki/index.php?title=Laser_Safety_Manual#L2I_floor_plan|L2I floor plan]] below for information about the location of each item.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE.<br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. The tables below detail the layout of each one, with the differential switches highlighted in blue.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board1.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
|bgcolor = "0088FF" | 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
|bgcolor = "0088FF" | 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 2'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board2.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=7 | Top<br />
| 1 || 40 || Differential switch for single phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets (Fastlite)<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| rowspan=3 | Middle<br />
| 8 || 40 || Differential switch for three-phase sockets<br />
|-<br />
| 9 || 16 || Three-phase socket B<br />
|-<br />
| 10 || 40 || Three-phase socket C<br />
|-<br />
| Bottom || 11 || 63 || Global panel circuit breaker<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 3'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board3.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=14 | Top<br />
| 1 || 16 || Single-phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| 8 || 16 || Single-phase sockets<br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || || <br />
|-<br />
| 11 || || <br />
|-<br />
| 12 || 10 || <br />
|-<br />
| 13 || 10 || <br />
|-<br />
|bgcolor = "0088FF" | 14 || 63 || <br />
|-<br />
| rowspan=7 | Middle<br />
| 15 || || Vacuum pump<br />
|-<br />
| 16 || || Overhead crane<br />
|-<br />
| 17 || || Three-phase socket<br />
|-<br />
|bgcolor = "0088FF" | 18 || 25 || Differential switch for circuit breakers 15-17 (?)<br />
|-<br />
| 19 || || Electrical panel 1<br />
|-<br />
| 20 || || Air Treatment Unit<br />
|-<br />
|bgcolor = "0088FF" | 21 || || <br />
|-<br />
| Bottom || || || Global panel switch<br />
<br />
|}<br />
<br />
==L2I floor plan==<br />
The figure below shows a schematic plan of L2I with items relevant to safety.<br /><br />
[[Ficheiro:L2I-Planta-legendas.png|50%|left|Flor plan of L2I.]]</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6077Laser Safety Manual2025-03-17T15:03:13Z<p>Ist23437: /* L2I floor plan */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
! Laser class !! Description !! Safety measures<br />
|-<br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
|| No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
|| Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
|| Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
|| Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
|rowspan="3"| '''Class 3''' ||colspan="2"| May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
|-<br />
|'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers. || Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
|-<br />
|'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers. || Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
|| Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also the section [[http://www.mysolutions.tecnico.ulisboa.pt/wiki/index.php?title=Laser_Safety_Manual#L2I_floor_plan|L2I floor plan]] below for information about the location of each item.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE.<br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. The tables below detail the layout of each one, with the differential switches highlighted in blue.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board1.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
|bgcolor = "0088FF" | 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
|bgcolor = "0088FF" | 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 2'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board2.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=7 | Top<br />
| 1 || 40 || Differential switch for single phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets (Fastlite)<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| rowspan=3 | Middle<br />
| 8 || 40 || Differential switch for three-phase sockets<br />
|-<br />
| 9 || 16 || Three-phase socket B<br />
|-<br />
| 10 || 40 || Three-phase socket C<br />
|-<br />
| Bottom || 11 || 63 || Global panel circuit breaker<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 3'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board3.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=14 | Top<br />
| 1 || 16 || Single-phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| 8 || 16 || Single-phase sockets<br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || || <br />
|-<br />
| 11 || || <br />
|-<br />
| 12 || 10 || <br />
|-<br />
| 13 || 10 || <br />
|-<br />
|bgcolor = "0088FF" | 14 || 63 || <br />
|-<br />
| rowspan=7 | Middle<br />
| 15 || || Vacuum pump<br />
|-<br />
| 16 || || Overhead crane<br />
|-<br />
| 17 || || Three-phase socket<br />
|-<br />
|bgcolor = "0088FF" | 18 || 25 || Differential switch for circuit breakers 15-17 (?)<br />
|-<br />
| 19 || || Electrical panel 1<br />
|-<br />
| 20 || || Air Treatment Unit<br />
|-<br />
|bgcolor = "0088FF" | 21 || || <br />
|-<br />
| Bottom || || || Global panel switch<br />
<br />
|}<br />
<br />
==L2I floor plan==<br />
The figure below shows a schematic plan of L2I with items relevant to safety.<br /><br />
[[Ficheiro:L2I-Planta-legendas.png|200px|left|Flor plan of L2I.]]</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6076Laser Safety Manual2025-03-17T15:02:06Z<p>Ist23437: /* L2I floor plan */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
! Laser class !! Description !! Safety measures<br />
|-<br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
|| No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
|| Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
|| Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
|| Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
|rowspan="3"| '''Class 3''' ||colspan="2"| May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
|-<br />
|'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers. || Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
|-<br />
|'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers. || Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
|| Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also the section [[http://www.mysolutions.tecnico.ulisboa.pt/wiki/index.php?title=Laser_Safety_Manual#L2I_floor_plan|L2I floor plan]] below for information about the location of each item.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE.<br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. The tables below detail the layout of each one, with the differential switches highlighted in blue.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board1.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
|bgcolor = "0088FF" | 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
|bgcolor = "0088FF" | 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 2'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board2.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=7 | Top<br />
| 1 || 40 || Differential switch for single phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets (Fastlite)<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| rowspan=3 | Middle<br />
| 8 || 40 || Differential switch for three-phase sockets<br />
|-<br />
| 9 || 16 || Three-phase socket B<br />
|-<br />
| 10 || 40 || Three-phase socket C<br />
|-<br />
| Bottom || 11 || 63 || Global panel circuit breaker<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 3'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board3.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=14 | Top<br />
| 1 || 16 || Single-phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| 8 || 16 || Single-phase sockets<br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || || <br />
|-<br />
| 11 || || <br />
|-<br />
| 12 || 10 || <br />
|-<br />
| 13 || 10 || <br />
|-<br />
|bgcolor = "0088FF" | 14 || 63 || <br />
|-<br />
| rowspan=7 | Middle<br />
| 15 || || Vacuum pump<br />
|-<br />
| 16 || || Overhead crane<br />
|-<br />
| 17 || || Three-phase socket<br />
|-<br />
|bgcolor = "0088FF" | 18 || 25 || Differential switch for circuit breakers 15-17 (?)<br />
|-<br />
| 19 || || Electrical panel 1<br />
|-<br />
| 20 || || Air Treatment Unit<br />
|-<br />
|bgcolor = "0088FF" | 21 || || <br />
|-<br />
| Bottom || || || Global panel switch<br />
<br />
|}<br />
<br />
==L2I floor plan==<br />
The figure below shows a schematic plan of L2I with items relevant to safety.<br /><br />
[[Ficheiro:L2I-Planta-legendas.png|esquerda]]<br />
[[Ficheiro:L2I-Planta-legendas.png|thumb|upright=0.25|Flor plan of L2I.]]</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6075Laser Safety Manual2025-03-17T15:01:27Z<p>Ist23437: /* L2I floor plan */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
! Laser class !! Description !! Safety measures<br />
|-<br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
|| No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
|| Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
|| Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
|| Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
|rowspan="3"| '''Class 3''' ||colspan="2"| May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
|-<br />
|'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers. || Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
|-<br />
|'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers. || Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
|| Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also the section [[http://www.mysolutions.tecnico.ulisboa.pt/wiki/index.php?title=Laser_Safety_Manual#L2I_floor_plan|L2I floor plan]] below for information about the location of each item.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE.<br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. The tables below detail the layout of each one, with the differential switches highlighted in blue.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board1.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
|bgcolor = "0088FF" | 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
|bgcolor = "0088FF" | 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 2'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board2.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=7 | Top<br />
| 1 || 40 || Differential switch for single phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets (Fastlite)<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| rowspan=3 | Middle<br />
| 8 || 40 || Differential switch for three-phase sockets<br />
|-<br />
| 9 || 16 || Three-phase socket B<br />
|-<br />
| 10 || 40 || Three-phase socket C<br />
|-<br />
| Bottom || 11 || 63 || Global panel circuit breaker<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 3'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board3.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=14 | Top<br />
| 1 || 16 || Single-phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| 8 || 16 || Single-phase sockets<br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || || <br />
|-<br />
| 11 || || <br />
|-<br />
| 12 || 10 || <br />
|-<br />
| 13 || 10 || <br />
|-<br />
|bgcolor = "0088FF" | 14 || 63 || <br />
|-<br />
| rowspan=7 | Middle<br />
| 15 || || Vacuum pump<br />
|-<br />
| 16 || || Overhead crane<br />
|-<br />
| 17 || || Three-phase socket<br />
|-<br />
|bgcolor = "0088FF" | 18 || 25 || Differential switch for circuit breakers 15-17 (?)<br />
|-<br />
| 19 || || Electrical panel 1<br />
|-<br />
| 20 || || Air Treatment Unit<br />
|-<br />
|bgcolor = "0088FF" | 21 || || <br />
|-<br />
| Bottom || || || Global panel switch<br />
<br />
|}<br />
<br />
==L2I floor plan==<br />
The figure below shows a schematic plan of L2I with items relevant to safety.<br /><br />
<br />
[[Ficheiro:L2I-Planta-legendas.png|thumb|upright=0.25|Flor plan of L2I.]]</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6074Laser Safety Manual2025-03-17T15:01:10Z<p>Ist23437: /* L2I floor plan */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
! Laser class !! Description !! Safety measures<br />
|-<br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
|| No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
|| Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
|| Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
|| Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
|rowspan="3"| '''Class 3''' ||colspan="2"| May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
|-<br />
|'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers. || Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
|-<br />
|'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers. || Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
|| Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also the section [[http://www.mysolutions.tecnico.ulisboa.pt/wiki/index.php?title=Laser_Safety_Manual#L2I_floor_plan|L2I floor plan]] below for information about the location of each item.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE.<br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. The tables below detail the layout of each one, with the differential switches highlighted in blue.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board1.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
|bgcolor = "0088FF" | 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
|bgcolor = "0088FF" | 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 2'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board2.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=7 | Top<br />
| 1 || 40 || Differential switch for single phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets (Fastlite)<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| rowspan=3 | Middle<br />
| 8 || 40 || Differential switch for three-phase sockets<br />
|-<br />
| 9 || 16 || Three-phase socket B<br />
|-<br />
| 10 || 40 || Three-phase socket C<br />
|-<br />
| Bottom || 11 || 63 || Global panel circuit breaker<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 3'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board3.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=14 | Top<br />
| 1 || 16 || Single-phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| 8 || 16 || Single-phase sockets<br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || || <br />
|-<br />
| 11 || || <br />
|-<br />
| 12 || 10 || <br />
|-<br />
| 13 || 10 || <br />
|-<br />
|bgcolor = "0088FF" | 14 || 63 || <br />
|-<br />
| rowspan=7 | Middle<br />
| 15 || || Vacuum pump<br />
|-<br />
| 16 || || Overhead crane<br />
|-<br />
| 17 || || Three-phase socket<br />
|-<br />
|bgcolor = "0088FF" | 18 || 25 || Differential switch for circuit breakers 15-17 (?)<br />
|-<br />
| 19 || || Electrical panel 1<br />
|-<br />
| 20 || || Air Treatment Unit<br />
|-<br />
|bgcolor = "0088FF" | 21 || || <br />
|-<br />
| Bottom || || || Global panel switch<br />
<br />
|}<br />
<br />
==L2I floor plan==<br />
The figure below shows a schematic plan of L2I with items relevant to safety.<br /><br />
<br />
[[Ficheiro:L2I-Planta-legendas.png|commoldura|upright=0.05|Flor plan of L2I.]]</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6073Laser Safety Manual2025-03-17T15:00:52Z<p>Ist23437: /* L2I floor plan */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
! Laser class !! Description !! Safety measures<br />
|-<br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
|| No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
|| Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
|| Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
|| Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
|rowspan="3"| '''Class 3''' ||colspan="2"| May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
|-<br />
|'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers. || Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
|-<br />
|'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers. || Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
|| Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also the section [[http://www.mysolutions.tecnico.ulisboa.pt/wiki/index.php?title=Laser_Safety_Manual#L2I_floor_plan|L2I floor plan]] below for information about the location of each item.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE.<br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. The tables below detail the layout of each one, with the differential switches highlighted in blue.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board1.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
|bgcolor = "0088FF" | 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
|bgcolor = "0088FF" | 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 2'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board2.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=7 | Top<br />
| 1 || 40 || Differential switch for single phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets (Fastlite)<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| rowspan=3 | Middle<br />
| 8 || 40 || Differential switch for three-phase sockets<br />
|-<br />
| 9 || 16 || Three-phase socket B<br />
|-<br />
| 10 || 40 || Three-phase socket C<br />
|-<br />
| Bottom || 11 || 63 || Global panel circuit breaker<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 3'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board3.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=14 | Top<br />
| 1 || 16 || Single-phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| 8 || 16 || Single-phase sockets<br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || || <br />
|-<br />
| 11 || || <br />
|-<br />
| 12 || 10 || <br />
|-<br />
| 13 || 10 || <br />
|-<br />
|bgcolor = "0088FF" | 14 || 63 || <br />
|-<br />
| rowspan=7 | Middle<br />
| 15 || || Vacuum pump<br />
|-<br />
| 16 || || Overhead crane<br />
|-<br />
| 17 || || Three-phase socket<br />
|-<br />
|bgcolor = "0088FF" | 18 || 25 || Differential switch for circuit breakers 15-17 (?)<br />
|-<br />
| 19 || || Electrical panel 1<br />
|-<br />
| 20 || || Air Treatment Unit<br />
|-<br />
|bgcolor = "0088FF" | 21 || || <br />
|-<br />
| Bottom || || || Global panel switch<br />
<br />
|}<br />
<br />
==L2I floor plan==<br />
The figure below shows a schematic plan of L2I with items relevant to safety.<br /><br />
<br />
[[Ficheiro:L2I-Planta-legendas.png|commoldura|upright=0.25|Flor plan of L2I.]]</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6072Laser Safety Manual2025-03-17T15:00:22Z<p>Ist23437: /* L2I floor plan */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
! Laser class !! Description !! Safety measures<br />
|-<br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
|| No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
|| Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
|| Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
|| Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
|rowspan="3"| '''Class 3''' ||colspan="2"| May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
|-<br />
|'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers. || Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
|-<br />
|'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers. || Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
|| Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also the section [[http://www.mysolutions.tecnico.ulisboa.pt/wiki/index.php?title=Laser_Safety_Manual#L2I_floor_plan|L2I floor plan]] below for information about the location of each item.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE.<br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. The tables below detail the layout of each one, with the differential switches highlighted in blue.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board1.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
|bgcolor = "0088FF" | 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
|bgcolor = "0088FF" | 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 2'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board2.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=7 | Top<br />
| 1 || 40 || Differential switch for single phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets (Fastlite)<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| rowspan=3 | Middle<br />
| 8 || 40 || Differential switch for three-phase sockets<br />
|-<br />
| 9 || 16 || Three-phase socket B<br />
|-<br />
| 10 || 40 || Three-phase socket C<br />
|-<br />
| Bottom || 11 || 63 || Global panel circuit breaker<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 3'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board3.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=14 | Top<br />
| 1 || 16 || Single-phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| 8 || 16 || Single-phase sockets<br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || || <br />
|-<br />
| 11 || || <br />
|-<br />
| 12 || 10 || <br />
|-<br />
| 13 || 10 || <br />
|-<br />
|bgcolor = "0088FF" | 14 || 63 || <br />
|-<br />
| rowspan=7 | Middle<br />
| 15 || || Vacuum pump<br />
|-<br />
| 16 || || Overhead crane<br />
|-<br />
| 17 || || Three-phase socket<br />
|-<br />
|bgcolor = "0088FF" | 18 || 25 || Differential switch for circuit breakers 15-17 (?)<br />
|-<br />
| 19 || || Electrical panel 1<br />
|-<br />
| 20 || || Air Treatment Unit<br />
|-<br />
|bgcolor = "0088FF" | 21 || || <br />
|-<br />
| Bottom || || || Global panel switch<br />
<br />
|}<br />
<br />
==L2I floor plan==<br />
The figure below shows a schematic plan of L2I with items relevant to safety.<br /><br />
<br />
[[Ficheiro:L2I-Planta-legendas.png|commoldura|upright=0.75|Flor plan of L2I.]]</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6071Laser Safety Manual2025-03-17T14:59:32Z<p>Ist23437: /* Preventive measures */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
! Laser class !! Description !! Safety measures<br />
|-<br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
|| No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
|| Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
|| Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
|| Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
|rowspan="3"| '''Class 3''' ||colspan="2"| May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
|-<br />
|'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers. || Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
|-<br />
|'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers. || Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
|| Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also the section [[http://www.mysolutions.tecnico.ulisboa.pt/wiki/index.php?title=Laser_Safety_Manual#L2I_floor_plan|L2I floor plan]] below for information about the location of each item.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE.<br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. The tables below detail the layout of each one, with the differential switches highlighted in blue.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board1.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
|bgcolor = "0088FF" | 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
|bgcolor = "0088FF" | 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 2'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board2.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=7 | Top<br />
| 1 || 40 || Differential switch for single phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets (Fastlite)<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| rowspan=3 | Middle<br />
| 8 || 40 || Differential switch for three-phase sockets<br />
|-<br />
| 9 || 16 || Three-phase socket B<br />
|-<br />
| 10 || 40 || Three-phase socket C<br />
|-<br />
| Bottom || 11 || 63 || Global panel circuit breaker<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 3'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board3.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=14 | Top<br />
| 1 || 16 || Single-phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| 8 || 16 || Single-phase sockets<br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || || <br />
|-<br />
| 11 || || <br />
|-<br />
| 12 || 10 || <br />
|-<br />
| 13 || 10 || <br />
|-<br />
|bgcolor = "0088FF" | 14 || 63 || <br />
|-<br />
| rowspan=7 | Middle<br />
| 15 || || Vacuum pump<br />
|-<br />
| 16 || || Overhead crane<br />
|-<br />
| 17 || || Three-phase socket<br />
|-<br />
|bgcolor = "0088FF" | 18 || 25 || Differential switch for circuit breakers 15-17 (?)<br />
|-<br />
| 19 || || Electrical panel 1<br />
|-<br />
| 20 || || Air Treatment Unit<br />
|-<br />
|bgcolor = "0088FF" | 21 || || <br />
|-<br />
| Bottom || || || Global panel switch<br />
<br />
|}<br />
<br />
==L2I floor plan==<br />
The figure below shows a schematic plan of L2I with items relevant to safety.<br />
[[Ficheiro:L2I-Planta-legendas.png|semmoldura|Flor plan of L2I.]]</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Ficheiro:L2I-Planta-legendas.png&diff=6070Ficheiro:L2I-Planta-legendas.png2025-03-17T14:57:48Z<p>Ist23437: </p>
<hr />
<div></div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6069Laser Safety Manual2025-03-17T14:57:30Z<p>Ist23437: /* Additional information */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
! Laser class !! Description !! Safety measures<br />
|-<br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
|| No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
|| Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
|| Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
|| Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
|rowspan="3"| '''Class 3''' ||colspan="2"| May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
|-<br />
|'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers. || Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
|-<br />
|'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers. || Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
|| Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. The tables below detail the layout of each one, with the differential switches highlighted in blue.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board1.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
|bgcolor = "0088FF" | 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
|bgcolor = "0088FF" | 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 2'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board2.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=7 | Top<br />
| 1 || 40 || Differential switch for single phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets (Fastlite)<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| rowspan=3 | Middle<br />
| 8 || 40 || Differential switch for three-phase sockets<br />
|-<br />
| 9 || 16 || Three-phase socket B<br />
|-<br />
| 10 || 40 || Three-phase socket C<br />
|-<br />
| Bottom || 11 || 63 || Global panel circuit breaker<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 3'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board3.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=14 | Top<br />
| 1 || 16 || Single-phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| 8 || 16 || Single-phase sockets<br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || || <br />
|-<br />
| 11 || || <br />
|-<br />
| 12 || 10 || <br />
|-<br />
| 13 || 10 || <br />
|-<br />
|bgcolor = "0088FF" | 14 || 63 || <br />
|-<br />
| rowspan=7 | Middle<br />
| 15 || || Vacuum pump<br />
|-<br />
| 16 || || Overhead crane<br />
|-<br />
| 17 || || Three-phase socket<br />
|-<br />
|bgcolor = "0088FF" | 18 || 25 || Differential switch for circuit breakers 15-17 (?)<br />
|-<br />
| 19 || || Electrical panel 1<br />
|-<br />
| 20 || || Air Treatment Unit<br />
|-<br />
|bgcolor = "0088FF" | 21 || || <br />
|-<br />
| Bottom || || || Global panel switch<br />
<br />
|}<br />
<br />
==L2I floor plan==<br />
The figure below shows a schematic plan of L2I with items relevant to safety.<br />
[[Ficheiro:L2I-Planta-legendas.png|semmoldura|Flor plan of L2I.]]</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6068Laser Safety Manual2025-03-17T12:55:06Z<p>Ist23437: /* Classification of lasers and laser systems */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
! Laser class !! Description !! Safety measures<br />
|-<br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
|| No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
|| Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
|| Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
|| Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
|rowspan="3"| '''Class 3''' ||colspan="2"| May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
|-<br />
|'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers. || Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
|-<br />
|'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers. || Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
|| Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. The tables below detail the layout of each one, with the differential switches highlighted in blue.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board1.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
|bgcolor = "0088FF" | 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
|bgcolor = "0088FF" | 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 2'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board2.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=7 | Top<br />
| 1 || 40 || Differential switch for single phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets (Fastlite)<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| rowspan=3 | Middle<br />
| 8 || 40 || Differential switch for three-phase sockets<br />
|-<br />
| 9 || 16 || Three-phase socket B<br />
|-<br />
| 10 || 40 || Three-phase socket C<br />
|-<br />
| Bottom || 11 || 63 || Global panel circuit breaker<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 3'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board3.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=14 | Top<br />
| 1 || 16 || Single-phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| 8 || 16 || Single-phase sockets<br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || || <br />
|-<br />
| 11 || || <br />
|-<br />
| 12 || 10 || <br />
|-<br />
| 13 || 10 || <br />
|-<br />
|bgcolor = "0088FF" | 14 || 63 || <br />
|-<br />
| rowspan=7 | Middle<br />
| 15 || || Vacuum pump<br />
|-<br />
| 16 || || Overhead crane<br />
|-<br />
| 17 || || Three-phase socket<br />
|-<br />
|bgcolor = "0088FF" | 18 || 25 || Differential switch for circuit breakers 15-17 (?)<br />
|-<br />
| 19 || || Electrical panel 1<br />
|-<br />
| 20 || || Air Treatment Unit<br />
|-<br />
|bgcolor = "0088FF" | 21 || || <br />
|-<br />
| Bottom || || || Global panel switch<br />
<br />
|}</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6067Laser Safety Manual2025-03-17T12:53:36Z<p>Ist23437: /* Classification of lasers and laser systems */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
! Laser class !! Description !! Safety measures<br />
|-<br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
|| No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
|| Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
|| Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
|| Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
|rowspan="3"| '''Class 3''' || colspan="2" May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
|-<br />
|'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers. || Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
|'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers. || Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
|| Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. The tables below detail the layout of each one, with the differential switches highlighted in blue.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board1.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
|bgcolor = "0088FF" | 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
|bgcolor = "0088FF" | 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 2'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board2.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=7 | Top<br />
| 1 || 40 || Differential switch for single phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets (Fastlite)<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| rowspan=3 | Middle<br />
| 8 || 40 || Differential switch for three-phase sockets<br />
|-<br />
| 9 || 16 || Three-phase socket B<br />
|-<br />
| 10 || 40 || Three-phase socket C<br />
|-<br />
| Bottom || 11 || 63 || Global panel circuit breaker<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 3'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board3.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=14 | Top<br />
| 1 || 16 || Single-phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| 8 || 16 || Single-phase sockets<br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || || <br />
|-<br />
| 11 || || <br />
|-<br />
| 12 || 10 || <br />
|-<br />
| 13 || 10 || <br />
|-<br />
|bgcolor = "0088FF" | 14 || 63 || <br />
|-<br />
| rowspan=7 | Middle<br />
| 15 || || Vacuum pump<br />
|-<br />
| 16 || || Overhead crane<br />
|-<br />
| 17 || || Three-phase socket<br />
|-<br />
|bgcolor = "0088FF" | 18 || 25 || Differential switch for circuit breakers 15-17 (?)<br />
|-<br />
| 19 || || Electrical panel 1<br />
|-<br />
| 20 || || Air Treatment Unit<br />
|-<br />
|bgcolor = "0088FF" | 21 || || <br />
|-<br />
| Bottom || || || Global panel switch<br />
<br />
|}</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6066Laser Safety Manual2025-03-17T12:52:22Z<p>Ist23437: /* Classification of lasers and laser systems */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
! Laser class !! Description !! Safety measures<br />
|-<br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
|| No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
|| Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
|| Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
|| Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
|rowspan="3"| '''Class 3''' || May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
<br />
'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers.<br />
<br />
|| Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
<br />
'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers.<br />
<br />
|| Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
|| Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. The tables below detail the layout of each one, with the differential switches highlighted in blue.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board1.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
|bgcolor = "0088FF" | 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
|bgcolor = "0088FF" | 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 2'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board2.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=7 | Top<br />
| 1 || 40 || Differential switch for single phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets (Fastlite)<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| rowspan=3 | Middle<br />
| 8 || 40 || Differential switch for three-phase sockets<br />
|-<br />
| 9 || 16 || Three-phase socket B<br />
|-<br />
| 10 || 40 || Three-phase socket C<br />
|-<br />
| Bottom || 11 || 63 || Global panel circuit breaker<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 3'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board3.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=14 | Top<br />
| 1 || 16 || Single-phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| 8 || 16 || Single-phase sockets<br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || || <br />
|-<br />
| 11 || || <br />
|-<br />
| 12 || 10 || <br />
|-<br />
| 13 || 10 || <br />
|-<br />
|bgcolor = "0088FF" | 14 || 63 || <br />
|-<br />
| rowspan=7 | Middle<br />
| 15 || || Vacuum pump<br />
|-<br />
| 16 || || Overhead crane<br />
|-<br />
| 17 || || Three-phase socket<br />
|-<br />
|bgcolor = "0088FF" | 18 || 25 || Differential switch for circuit breakers 15-17 (?)<br />
|-<br />
| 19 || || Electrical panel 1<br />
|-<br />
| 20 || || Air Treatment Unit<br />
|-<br />
|bgcolor = "0088FF" | 21 || || <br />
|-<br />
| Bottom || || || Global panel switch<br />
<br />
|}</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6065Laser Safety Manual2025-03-17T12:50:35Z<p>Ist23437: /* Classification of lasers and laser systems */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
!style="width: 10%"! Laser class !! Description !! Safety measures<br />
|-<br />
| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
|| No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
|| Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
|| Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
|| Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
| '''Class 3''' || May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
<br />
'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers.<br />
<br />
|| Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
<br />
'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers.<br />
<br />
|| Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
|| Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. The tables below detail the layout of each one, with the differential switches highlighted in blue.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board1.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
|bgcolor = "0088FF" | 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
|bgcolor = "0088FF" | 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 2'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board2.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=7 | Top<br />
| 1 || 40 || Differential switch for single phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets (Fastlite)<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| rowspan=3 | Middle<br />
| 8 || 40 || Differential switch for three-phase sockets<br />
|-<br />
| 9 || 16 || Three-phase socket B<br />
|-<br />
| 10 || 40 || Three-phase socket C<br />
|-<br />
| Bottom || 11 || 63 || Global panel circuit breaker<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 3'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board3.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=14 | Top<br />
| 1 || 16 || Single-phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| 8 || 16 || Single-phase sockets<br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || || <br />
|-<br />
| 11 || || <br />
|-<br />
| 12 || 10 || <br />
|-<br />
| 13 || 10 || <br />
|-<br />
|bgcolor = "0088FF" | 14 || 63 || <br />
|-<br />
| rowspan=7 | Middle<br />
| 15 || || Vacuum pump<br />
|-<br />
| 16 || || Overhead crane<br />
|-<br />
| 17 || || Three-phase socket<br />
|-<br />
|bgcolor = "0088FF" | 18 || 25 || Differential switch for circuit breakers 15-17 (?)<br />
|-<br />
| 19 || || Electrical panel 1<br />
|-<br />
| 20 || || Air Treatment Unit<br />
|-<br />
|bgcolor = "0088FF" | 21 || || <br />
|-<br />
| Bottom || || || Global panel switch<br />
<br />
|}</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6064Laser Safety Manual2025-03-17T12:38:40Z<p>Ist23437: /* Electric panels */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
'''Safety Measures:''' No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
'''Safety Measures:''' Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
| '''Class 3''' || May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
<br />
'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers.<br />
<br />
'''Safety Measures:''' Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
<br />
'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers.<br />
<br />
'''Safety Measures:''' Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
'''Safety Measures:''' Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. The tables below detail the layout of each one, with the differential switches highlighted in blue.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board1.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
|bgcolor = "0088FF" | 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
|bgcolor = "0088FF" | 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 2'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board2.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=7 | Top<br />
| 1 || 40 || Differential switch for single phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets (Fastlite)<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| rowspan=3 | Middle<br />
| 8 || 40 || Differential switch for three-phase sockets<br />
|-<br />
| 9 || 16 || Three-phase socket B<br />
|-<br />
| 10 || 40 || Three-phase socket C<br />
|-<br />
| Bottom || 11 || 63 || Global panel circuit breaker<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 3'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board3.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=14 | Top<br />
| 1 || 16 || Single-phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| 8 || 16 || Single-phase sockets<br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || || <br />
|-<br />
| 11 || || <br />
|-<br />
| 12 || 10 || <br />
|-<br />
| 13 || 10 || <br />
|-<br />
|bgcolor = "0088FF" | 14 || 63 || <br />
|-<br />
| rowspan=7 | Middle<br />
| 15 || || Vacuum pump<br />
|-<br />
| 16 || || Overhead crane<br />
|-<br />
| 17 || || Three-phase socket<br />
|-<br />
|bgcolor = "0088FF" | 18 || 25 || Differential switch for circuit breakers 15-17 (?)<br />
|-<br />
| 19 || || Electrical panel 1<br />
|-<br />
| 20 || || Air Treatment Unit<br />
|-<br />
|bgcolor = "0088FF" | 21 || || <br />
|-<br />
| Bottom || || || Global panel switch<br />
<br />
|}</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6063Laser Safety Manual2025-03-17T12:37:43Z<p>Ist23437: /* Electric panels */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
'''Safety Measures:''' No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
'''Safety Measures:''' Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
| '''Class 3''' || May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
<br />
'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers.<br />
<br />
'''Safety Measures:''' Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
<br />
'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers.<br />
<br />
'''Safety Measures:''' Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
'''Safety Measures:''' Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. The tables below detail the layout of each electrical panel.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board1.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
|bgcolor = "0088FF" | 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
|bgcolor = "0088FF" | 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 2'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board2.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=7 | Top<br />
| 1 || 40 || Differential switch for single phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets (Fastlite)<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| rowspan=3 | Middle<br />
| 8 || 40 || Differential switch for three-phase sockets<br />
|-<br />
| 9 || 16 || Three-phase socket B<br />
|-<br />
| 10 || 40 || Three-phase socket C<br />
|-<br />
| Bottom || 11 || 63 || Global panel circuit breaker<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 3'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board3.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=14 | Top<br />
| 1 || 16 || Single-phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| 8 || 16 || Single-phase sockets<br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || || <br />
|-<br />
| 11 || || <br />
|-<br />
| 12 || 10 || <br />
|-<br />
| 13 || 10 || <br />
|-<br />
|bgcolor = "0088FF" | 14 || 63 || <br />
|-<br />
| rowspan=7 | Middle<br />
| 15 || || Vacuum pump<br />
|-<br />
| 16 || || Overhead crane<br />
|-<br />
| 17 || || Three-phase socket<br />
|-<br />
|bgcolor = "0088FF" | 18 || 25 || Differential switch for circuit breakers 15-17 (?)<br />
|-<br />
| 19 || || Electrical panel 1<br />
|-<br />
| 20 || || Air Treatment Unit<br />
|-<br />
|bgcolor = "0088FF" | 21 || || <br />
|-<br />
| Bottom || || || Global panel switch<br />
<br />
|}</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6062Laser Safety Manual2025-03-17T12:37:21Z<p>Ist23437: /* Electric panels */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
'''Safety Measures:''' No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
'''Safety Measures:''' Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
| '''Class 3''' || May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
<br />
'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers.<br />
<br />
'''Safety Measures:''' Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
<br />
'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers.<br />
<br />
'''Safety Measures:''' Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
'''Safety Measures:''' Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. The tables below detail the layout of each electrical panel.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
| colspan=4 style="text-align: center;" | [[Ficheiro:L2i electrical board1.png|miniaturadaimagem|center]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
|bgcolor = "0088FF" | 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
|bgcolor = "0088FF" | 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 2'''<br />
|-<br />
| colspan=4 |[[Ficheiro:L2i electrical board2.png|miniaturadaimagem]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=7 | Top<br />
| 1 || 40 || Differential switch for single phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets (Fastlite)<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| rowspan=3 | Middle<br />
| 8 || 40 || Differential switch for three-phase sockets<br />
|-<br />
| 9 || 16 || Three-phase socket B<br />
|-<br />
| 10 || 40 || Three-phase socket C<br />
|-<br />
| Bottom || 11 || 63 || Global panel circuit breaker<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 3'''<br />
|-<br />
| colspan=4 |[[Ficheiro:L2i electrical board3.png|miniaturadaimagem]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=14 | Top<br />
| 1 || 16 || Single-phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| 8 || 16 || Single-phase sockets<br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || || <br />
|-<br />
| 11 || || <br />
|-<br />
| 12 || 10 || <br />
|-<br />
| 13 || 10 || <br />
|-<br />
|bgcolor = "0088FF" | 14 || 63 || <br />
|-<br />
| rowspan=7 | Middle<br />
| 15 || || Vacuum pump<br />
|-<br />
| 16 || || Overhead crane<br />
|-<br />
| 17 || || Three-phase socket<br />
|-<br />
|bgcolor = "0088FF" | 18 || 25 || Differential switch for circuit breakers 15-17 (?)<br />
|-<br />
| 19 || || Electrical panel 1<br />
|-<br />
| 20 || || Air Treatment Unit<br />
|-<br />
|bgcolor = "0088FF" | 21 || || <br />
|-<br />
| Bottom || || || Global panel switch<br />
<br />
|}</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6061Laser Safety Manual2025-03-17T12:35:08Z<p>Ist23437: /* Electric panels */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
'''Safety Measures:''' No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
'''Safety Measures:''' Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
| '''Class 3''' || May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
<br />
'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers.<br />
<br />
'''Safety Measures:''' Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
<br />
'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers.<br />
<br />
'''Safety Measures:''' Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
'''Safety Measures:''' Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. The tables below detail the layout of each electrical panel.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
| colspan=4 style="text-align: center;" |[[Ficheiro:L2i electrical board1.png|miniaturadaimagem]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
|bgcolor = "0088FF" | 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
|bgcolor = "0088FF" | 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 2'''<br />
|-<br />
| colspan=4 |[[Ficheiro:L2i electrical board2.png|miniaturadaimagem]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=7 | Top<br />
| 1 || 40 || Differential switch for single phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets (Fastlite)<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| rowspan=3 | Middle<br />
| 8 || 40 || Differential switch for three-phase sockets<br />
|-<br />
| 9 || 16 || Three-phase socket B<br />
|-<br />
| 10 || 40 || Three-phase socket C<br />
|-<br />
| Bottom || 11 || 63 || Global panel circuit breaker<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 3'''<br />
|-<br />
| colspan=4 |[[Ficheiro:L2i electrical board3.png|miniaturadaimagem]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=14 | Top<br />
| 1 || 16 || Single-phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| 8 || 16 || Single-phase sockets<br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || || <br />
|-<br />
| 11 || || <br />
|-<br />
| 12 || 10 || <br />
|-<br />
| 13 || 10 || <br />
|-<br />
|bgcolor = "0088FF" | 14 || 63 || <br />
|-<br />
| rowspan=7 | Middle<br />
| 15 || || Vacuum pump<br />
|-<br />
| 16 || || Overhead crane<br />
|-<br />
| 17 || || Three-phase socket<br />
|-<br />
|bgcolor = "0088FF" | 18 || 25 || Differential switch for circuit breakers 15-17 (?)<br />
|-<br />
| 19 || || Electrical panel 1<br />
|-<br />
| 20 || || Air Treatment Unit<br />
|-<br />
|bgcolor = "0088FF" | 21 || || <br />
|-<br />
| Bottom || || || Global panel switch<br />
<br />
|}</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6060Laser Safety Manual2025-03-17T12:33:29Z<p>Ist23437: /* Electric panels */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
'''Safety Measures:''' No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
'''Safety Measures:''' Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
| '''Class 3''' || May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
<br />
'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers.<br />
<br />
'''Safety Measures:''' Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
<br />
'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers.<br />
<br />
'''Safety Measures:''' Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
'''Safety Measures:''' Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. The tables below detail the layout of each electrical panel.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
| colspan=4 |[[Ficheiro:L2i electrical board1.png|miniaturadaimagem]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
|bgcolor = "0088FF" | 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
|bgcolor = "0088FF" | 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 2'''<br />
|-<br />
| colspan=4 |[[Ficheiro:L2i electrical board2.png|miniaturadaimagem]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=7 | Top<br />
| 1 || 40 || Differential switch for single phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets (Fastlite)<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| rowspan=3 | Middle<br />
| 8 || 40 || Differential switch for three-phase sockets<br />
|-<br />
| 9 || 16 || Three-phase socket B<br />
|-<br />
| 10 || 40 || Three-phase socket C<br />
|-<br />
| Bottom || 11 || 63 || Global panel circuit breaker<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 3'''<br />
|-<br />
| colspan=4 |[[Ficheiro:L2i electrical board3.png|miniaturadaimagem]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=14 | Top<br />
| 1 || 16 || Single-phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| 8 || 16 || Single-phase sockets<br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || || <br />
|-<br />
| 11 || || <br />
|-<br />
| 12 || 10 || <br />
|-<br />
| 13 || 10 || <br />
|-<br />
|bgcolor = "0088FF" | 14 || 63 || <br />
|-<br />
| rowspan=7 | Middle<br />
| 15 || || Vacuum pump<br />
|-<br />
| 16 || || Overhead crane<br />
|-<br />
| 17 || || Three-phase socket<br />
|-<br />
|bgcolor = "0088FF" | 18 || 25 || Differential switch for circuit breakers 15-17 (?)<br />
|-<br />
| 19 || || Electrical panel 1<br />
|-<br />
| 20 || || Air Treatment Unit<br />
|-<br />
|bgcolor = "0088FF" | 21 || || <br />
|-<br />
| Bottom || || || Global panel switch<br />
<br />
|}</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6059Laser Safety Manual2025-03-17T12:32:52Z<p>Ist23437: /* Electric panels */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
'''Safety Measures:''' No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
'''Safety Measures:''' Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
| '''Class 3''' || May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
<br />
'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers.<br />
<br />
'''Safety Measures:''' Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
<br />
'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers.<br />
<br />
'''Safety Measures:''' Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
'''Safety Measures:''' Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. The tables below detail the layout of each electrical panel.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
| colspan=4 |[[Ficheiro:L2i electrical board1.png|miniaturadaimagem]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
|bgcolor = "0088FF" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
| 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
| 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 2'''<br />
|-<br />
| colspan=4 |[[Ficheiro:L2i electrical board2.png|miniaturadaimagem]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=7 | Top<br />
| 1 || 40 || Differential switch for single phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets (Fastlite)<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| rowspan=3 | Middle<br />
| 8 || 40 || Differential switch for three-phase sockets<br />
|-<br />
| 9 || 16 || Three-phase socket B<br />
|-<br />
| 10 || 40 || Three-phase socket C<br />
|-<br />
| Bottom || 11 || 63 || Global panel circuit breaker<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 3'''<br />
|-<br />
| colspan=4 |[[Ficheiro:L2i electrical board3.png|miniaturadaimagem]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=14 | Top<br />
| 1 || 16 || Single-phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| 8 || 16 || Single-phase sockets<br />
|-<br />
| 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || || <br />
|-<br />
| 11 || || <br />
|-<br />
| 12 || 10 || <br />
|-<br />
| 13 || 10 || <br />
|-<br />
| 14 || 63 || <br />
|-<br />
| rowspan=7 | Middle<br />
| 15 || || Vacuum pump<br />
|-<br />
| 16 || || Overhead crane<br />
|-<br />
| 17 || || Three-phase socket<br />
|-<br />
| 18 || 25 || Differential switch for circuit breakers 15-17 (?)<br />
|-<br />
| 19 || || Electrical panel 1<br />
|-<br />
| 20 || || Air Treatment Unit<br />
|-<br />
| 21 || || <br />
|-<br />
| Bottom || || || Global panel switch<br />
<br />
|}</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6058Laser Safety Manual2025-03-17T12:31:53Z<p>Ist23437: /* Electric panels */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
'''Safety Measures:''' No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
'''Safety Measures:''' Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
| '''Class 3''' || May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
<br />
'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers.<br />
<br />
'''Safety Measures:''' Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
<br />
'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers.<br />
<br />
'''Safety Measures:''' Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
'''Safety Measures:''' Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. The tables below detail the layout of each electrical panel.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
| colspan=4 |[[Ficheiro:L2i electrical board1.png|miniaturadaimagem]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
|bgcolor = "08F" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
| 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
| 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 2'''<br />
|-<br />
| colspan=4 |[[Ficheiro:L2i electrical board2.png|miniaturadaimagem]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=7 | Top<br />
| 1 || 40 || Differential switch for single phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets (Fastlite)<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| rowspan=3 | Middle<br />
| 8 || 40 || Differential switch for three-phase sockets<br />
|-<br />
| 9 || 16 || Three-phase socket B<br />
|-<br />
| 10 || 40 || Three-phase socket C<br />
|-<br />
| Bottom || 11 || 63 || Global panel circuit breaker<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 3'''<br />
|-<br />
| colspan=4 |[[Ficheiro:L2i electrical board3.png|miniaturadaimagem]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=14 | Top<br />
| 1 || 16 || Single-phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| 8 || 16 || Single-phase sockets<br />
|-<br />
| 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || || <br />
|-<br />
| 11 || || <br />
|-<br />
| 12 || 10 || <br />
|-<br />
| 13 || 10 || <br />
|-<br />
| 14 || 63 || <br />
|-<br />
| rowspan=7 | Middle<br />
| 15 || || Vacuum pump<br />
|-<br />
| 16 || || Overhead crane<br />
|-<br />
| 17 || || Three-phase socket<br />
|-<br />
| 18 || 25 || Differential switch for circuit breakers 15-17 (?)<br />
|-<br />
| 19 || || Electrical panel 1<br />
|-<br />
| 20 || || Air Treatment Unit<br />
|-<br />
| 21 || || <br />
|-<br />
| Bottom || || || Global panel switch<br />
<br />
|}</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6057Laser Safety Manual2025-03-17T12:30:12Z<p>Ist23437: /* Electric panels */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
'''Safety Measures:''' No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
'''Safety Measures:''' Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
| '''Class 3''' || May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
<br />
'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers.<br />
<br />
'''Safety Measures:''' Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
<br />
'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers.<br />
<br />
'''Safety Measures:''' Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
'''Safety Measures:''' Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. The tables below detail the layout of each electrical panel.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
| colspan=4 |[[Ficheiro:L2i electrical board1.png|miniaturadaimagem]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
|bgcolor = "blue" | 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
| 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
| 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 2'''<br />
|-<br />
| colspan=4 |[[Ficheiro:L2i electrical board2.png|miniaturadaimagem]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=7 | Top<br />
| 1 || 40 || Differential switch for single phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets (Fastlite)<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| rowspan=3 | Middle<br />
| 8 || 40 || Differential switch for three-phase sockets<br />
|-<br />
| 9 || 16 || Three-phase socket B<br />
|-<br />
| 10 || 40 || Three-phase socket C<br />
|-<br />
| Bottom || 11 || 63 || Global panel circuit breaker<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 3'''<br />
|-<br />
| colspan=4 |[[Ficheiro:L2i electrical board3.png|miniaturadaimagem]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=14 | Top<br />
| 1 || 16 || Single-phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| 8 || 16 || Single-phase sockets<br />
|-<br />
| 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || || <br />
|-<br />
| 11 || || <br />
|-<br />
| 12 || 10 || <br />
|-<br />
| 13 || 10 || <br />
|-<br />
| 14 || 63 || <br />
|-<br />
| rowspan=7 | Middle<br />
| 15 || || Vacuum pump<br />
|-<br />
| 16 || || Overhead crane<br />
|-<br />
| 17 || || Three-phase socket<br />
|-<br />
| 18 || 25 || Differential switch for circuit breakers 15-17 (?)<br />
|-<br />
| 19 || || Electrical panel 1<br />
|-<br />
| 20 || || Air Treatment Unit<br />
|-<br />
| 21 || || <br />
|-<br />
| Bottom || || || Global panel switch<br />
<br />
|}</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6056Laser Safety Manual2025-03-17T12:28:43Z<p>Ist23437: /* Electric panels */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
'''Safety Measures:''' No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
'''Safety Measures:''' Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
| '''Class 3''' || May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
<br />
'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers.<br />
<br />
'''Safety Measures:''' Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
<br />
'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers.<br />
<br />
'''Safety Measures:''' Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
'''Safety Measures:''' Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. The tables below detail the layout of each electrical panel.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
| colspan=4 |[[Ficheiro:L2i electrical board1.png|miniaturadaimagem]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
| 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
| 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
| 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 2'''<br />
|-<br />
| colspan=4 |[[Ficheiro:L2i electrical board2.png|miniaturadaimagem]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=7 | Top<br />
| 1 || 40 || Differential switch for single phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets (Fastlite)<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| rowspan=3 | Middle<br />
| 8 || 40 || Differential switch for three-phase sockets<br />
|-<br />
| 9 || 16 || Three-phase socket B<br />
|-<br />
| 10 || 40 || Three-phase socket C<br />
|-<br />
| Bottom || 11 || 63 || Global panel circuit breaker<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 3'''<br />
|-<br />
| colspan=4 |[[Ficheiro:L2i electrical board3.png|miniaturadaimagem]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=14 | Top<br />
| 1 || 16 || Single-phase sockets<br />
|-<br />
| 2 || 16 || Single-phase sockets<br />
|-<br />
| 3 || 16 || Single-phase sockets<br />
|-<br />
| 4 || 16 || Single-phase sockets<br />
|-<br />
| 5 || 16 || Single-phase sockets<br />
|-<br />
| 6 || 16 || Single-phase sockets<br />
|-<br />
| 7 || 16 || Single-phase sockets<br />
|-<br />
| 8 || 16 || Single-phase sockets<br />
|-<br />
| 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || || <br />
|-<br />
| 11 || || <br />
|-<br />
| 12 || 10 || <br />
|-<br />
| 13 || 10 || <br />
|-<br />
| 14 || 63 || <br />
|-<br />
| rowspan=7 | Middle<br />
| 15 || || Vacuum pump<br />
|-<br />
| 16 || || Overhead crane<br />
|-<br />
| 17 || || Three-phase socket<br />
|-<br />
| 18 || 25 || Differential switch for circuit breakers 15-17 (?)<br />
|-<br />
| 19 || || Electrical panel 1<br />
|-<br />
| 20 || || Air Treatment Unit<br />
|-<br />
| 21 || || <br />
| Bottom || || || Global panel switch<br />
<br />
|}</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6055Laser Safety Manual2025-03-17T12:23:28Z<p>Ist23437: /* Electric panels */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
'''Safety Measures:''' No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
'''Safety Measures:''' Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
| '''Class 3''' || May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
<br />
'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers.<br />
<br />
'''Safety Measures:''' Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
<br />
'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers.<br />
<br />
'''Safety Measures:''' Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
'''Safety Measures:''' Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. Check the figures below for detailed information.<br />
<br />
{| class="wikitable"<br />
|+ L2I electrical panels<br />
|-<br />
! Texto do cabeçalho !! Texto do cabeçalho !! Texto do cabeçalho<br />
|-<br />
| <br />
[[Ficheiro:L2i electrical board1.png|miniaturadaimagem]]<br />
|| [[Ficheiro:L2i electrical board2.png|miniaturadaimagem]] || [[Ficheiro:L2i electrical board3.png|miniaturadaimagem]]<br />
|-<br />
| Panel 1 || Panel 2 || Panel 3<br />
|}<br />
<br />
The tables below detail the layout of each electrical panel.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
| colspan=4 |[[Ficheiro:L2i electrical board1.png|miniaturadaimagem]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
| 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
| 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
| 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
|}<br />
<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 2'''<br />
|-<br />
| colspan=4 |[[Ficheiro:L2i electrical board2.png|miniaturadaimagem]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=7 | Top<br />
| 1 || 40 || Differential switch for single phase sockets<br />
|-<br />
| 2 || 16 || Sockets (Fastlite)<br />
|-<br />
| 3 || 16 || Sockets<br />
|-<br />
| 4 || 16 || Sockets<br />
|-<br />
| 5 || 16 || Sockets<br />
|-<br />
| 6 || 16 || Sockets<br />
|-<br />
| 7 || 16 || Sockets<br />
|-<br />
| rowspan=3 | Middle<br />
| 8 || 40 || Differential switch for three-phase sockets<br />
|-<br />
| 9 || 16 || Three-phase socket B<br />
|-<br />
| 10 || 40 || Three-phase socket C<br />
|-<br />
| Bottom || 11 || 63 || Global panel circuit breaker<br />
|}</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6054Laser Safety Manual2025-03-17T12:20:41Z<p>Ist23437: /* Electric panels */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
'''Safety Measures:''' No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
'''Safety Measures:''' Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
| '''Class 3''' || May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
<br />
'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers.<br />
<br />
'''Safety Measures:''' Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
<br />
'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers.<br />
<br />
'''Safety Measures:''' Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
'''Safety Measures:''' Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. Check the figures below for detailed information.<br />
<br />
{| class="wikitable"<br />
|+ L2I electrical panels<br />
|-<br />
! Texto do cabeçalho !! Texto do cabeçalho !! Texto do cabeçalho<br />
|-<br />
| <br />
[[Ficheiro:L2i electrical board1.png|miniaturadaimagem]]<br />
|| [[Ficheiro:L2i electrical board2.png|miniaturadaimagem]] || [[Ficheiro:L2i electrical board3.png|miniaturadaimagem]]<br />
|-<br />
| Panel 1 || Panel 2 || Panel 3<br />
|}<br />
<br />
The tables below detail the layout of each electrical panel.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
| colspan=3 |[[Ficheiro:L2i electrical board1.png|miniaturadaimagem]]<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
| 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
| 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
| 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
<br />
|}</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6053Laser Safety Manual2025-03-17T12:19:34Z<p>Ist23437: /* Electric panels */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
'''Safety Measures:''' No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
'''Safety Measures:''' Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
| '''Class 3''' || May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
<br />
'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers.<br />
<br />
'''Safety Measures:''' Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
<br />
'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers.<br />
<br />
'''Safety Measures:''' Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
'''Safety Measures:''' Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. Check the figures below for detailed information.<br />
<br />
{| class="wikitable"<br />
|+ L2I electrical panels<br />
|-<br />
! Texto do cabeçalho !! Texto do cabeçalho !! Texto do cabeçalho<br />
|-<br />
| <br />
[[Ficheiro:L2i electrical board1.png|miniaturadaimagem]]<br />
|| [[Ficheiro:L2i electrical board2.png|miniaturadaimagem]] || [[Ficheiro:L2i electrical board3.png|miniaturadaimagem]]<br />
|-<br />
| Panel 1 || Panel 2 || Panel 3<br />
|}<br />
<br />
The tables below detail the layout of each electrical panel.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
| 9 || 40 || Differential switch for circuit breakers 1-8<br />
|-<br />
| 10 || 40 || <br />
|-<br />
| 11 || 40 || <br />
|-<br />
| 12 || 63 || Differential switch for circuit breakers 10-11<br />
|-<br />
| 13 || 10 || Lighting, north side of main hall<br />
|-<br />
| 14 || 10 || Lighting, top floor<br />
|-<br />
| 15 || 25 || Differential switch for circuit breakers 13-14<br />
|-<br />
| rowspan=2 | Bottom <br />
| 1 || 100 || Global L2I circuit breaker<br />
|-<br />
| 2 || 40 || Overhead circuit breaker (Amphos laser)<br />
<br />
|}</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6052Laser Safety Manual2025-03-17T12:08:44Z<p>Ist23437: /* Electric panels */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
'''Safety Measures:''' No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
'''Safety Measures:''' Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
| '''Class 3''' || May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
<br />
'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers.<br />
<br />
'''Safety Measures:''' Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
<br />
'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers.<br />
<br />
'''Safety Measures:''' Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
'''Safety Measures:''' Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. Check the figures below for detailed information.<br />
<br />
{| class="wikitable"<br />
|+ L2I electrical panels<br />
|-<br />
! Texto do cabeçalho !! Texto do cabeçalho !! Texto do cabeçalho<br />
|-<br />
| <br />
[[Ficheiro:L2i electrical board1.png|miniaturadaimagem]]<br />
|| [[Ficheiro:L2i electrical board2.png|miniaturadaimagem]] || [[Ficheiro:L2i electrical board3.png|miniaturadaimagem]]<br />
|-<br />
| Panel 1 || Panel 2 || Panel 3<br />
|}<br />
<br />
The tables below detail the layout of each electrical panel.<br />
<br />
{| class="wikitable"<br />
|+ '''Panel 1'''<br />
|-<br />
! Slot !! No. !! Amps !! Description<br />
|-<br />
| rowspan=15 | Middle <br />
| 1 || 16 || <br />
|-<br />
| 2 || 16 || Top floor electrical sockets<br />
|-<br />
| 3 || 16 || Top floor electrical sockets<br />
|-<br />
| 4 || 16 || <br />
|-<br />
| 5 || 16 || <br />
|-<br />
| 6 || 16 || <br />
|-<br />
| 7 || 16 || <br />
|-<br />
| 8 || 16 || <br />
|-<br />
| 9 || 16 || <br />
|-<br />
| 10 || 16 || <br />
|-<br />
| 11 || 16 || <br />
|-<br />
| 12 || 16 || <br />
|-<br />
| 13 || 16 || <br />
|-<br />
| 14 || 16 || <br />
|-<br />
| 15 || 16 || <br />
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<div></div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6048Laser Safety Manual2025-03-17T12:03:48Z<p>Ist23437: /* Preventive measures */</p>
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<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
'''Safety Measures:''' No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
'''Safety Measures:''' Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
| '''Class 3''' || May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
<br />
'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers.<br />
<br />
'''Safety Measures:''' Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
<br />
'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers.<br />
<br />
'''Safety Measures:''' Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
'''Safety Measures:''' Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || Ceiling (lights) and walking paths (tape) ||In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
==Electric panels==<br />
L2I is equipped with three electrical panels. The main one is Panel 3. Check the figures below for detailed information.<br />
<br />
{| class="wikitable"<br />
|+ L2I electrical panels<br />
|-<br />
! Texto do cabeçalho !! Texto do cabeçalho !! Texto do cabeçalho<br />
|-<br />
| <br />
[[Ficheiro:L2i electrical board1.png|miniaturadaimagem]]<br />
|| [[Ficheiro:L2i electrical board2.png|miniaturadaimagem]] || [[Ficheiro:L2i electrical board3.png|miniaturadaimagem]]<br />
|-<br />
| Panel 1 || Panel 2 || Panel 3<br />
|}<br />
<br />
<br />
<br />
The tables below detail the layout of the electrical panels.</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6047Laser Safety Manual2025-03-17T11:59:30Z<p>Ist23437: /* Preventive measures */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
'''Safety Measures:''' No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
'''Safety Measures:''' Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
| '''Class 3''' || May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
<br />
'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers.<br />
<br />
'''Safety Measures:''' Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
<br />
'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers.<br />
<br />
'''Safety Measures:''' Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
'''Safety Measures:''' Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || To the right of the main door, inside the laboratory || In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door|| East wall, three-door exit || In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
7.2 Electric panels<br />
L2I is equipped with three electrical panels. The main one is Panel 3.<br />
<br />
Panel 1 Panel 2 Panel 3<br />
<br />
The tables below detail the layout of the electrical panels.</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6046Laser Safety Manual2025-03-17T11:58:26Z<p>Ist23437: /* Preventive measures */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
'''Safety Measures:''' No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
'''Safety Measures:''' Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
| '''Class 3''' || May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
<br />
'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers.<br />
<br />
'''Safety Measures:''' Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
<br />
'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers.<br />
<br />
'''Safety Measures:''' Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
'''Safety Measures:''' Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Location !! Description <br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || North wall || General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || South wall || Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Ceiling || Automated smoke detector connected to a central alarm system.<br />
|-<br />
|Portable extinguishers || North wall and next to the basin || CO2 fire extinguishers, suitable for electrical fires and flammable liquids. Make sure to ventilate the area after using, as CO2 displaces oxygen.<br />
|-<br />
Interlock system || Changing room || Panel displaying the status (on/off) of the Amphos laser.<br />
|-<br />
|First aid kit || North wall || Basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Changing room || Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks.<br />
|-<br />
|Laser goggles || Changing room || Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || Location: to the right of the main door, inside the laboratory<br />In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door Location: East wall, three-door exit<br />In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
7.2 Electric panels<br />
L2I is equipped with three electrical panels. The main one is Panel 3.<br />
<br />
Panel 1 Panel 2 Panel 3<br />
<br />
The tables below detail the layout of the electrical panels.</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Ficheiro:L2i_warning_sign.png&diff=6045Ficheiro:L2i warning sign.png2025-03-17T11:48:24Z<p>Ist23437: </p>
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<div></div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6044Laser Safety Manual2025-03-17T11:48:13Z<p>Ist23437: /* Control measures */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
'''Safety Measures:''' No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
'''Safety Measures:''' Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
| '''Class 3''' || May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
<br />
'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers.<br />
<br />
'''Safety Measures:''' Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
<br />
'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers.<br />
<br />
'''Safety Measures:''' Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
'''Safety Measures:''' Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || <br />
[[Ficheiro:L2i warning sign.png|miniaturadaimagem|Laser status sign next to the door into L2I.]]<br />
Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Description<br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || Location: north wall <br />General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || Location: south wall<br />Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Location: ceiling<br />
|-<br />
|Portable extinguishers || Location: north wall and next to the basin<br />
|-<br />
Interlock system || Location: before the main room<br />
|-<br />
|First aid kit || Location: north wall<br />A basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Location: before the main room<br />Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks<br />
|-<br />
|Laser goggles || Location: before the main room<br />
Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || Location: to the right of the main door, inside the laboratory<br />In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door Location: East wall, three-door exit<br />In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
7.2 Electric panels<br />
L2I is equipped with three electrical panels. The main one is Panel 3.<br />
<br />
Panel 1 Panel 2 Panel 3<br />
<br />
The tables below detail the layout of the electrical panels.</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6043Laser Safety Manual2025-03-17T11:46:21Z<p>Ist23437: /* Lifting heavy objects using the crane */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
'''Safety Measures:''' No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
'''Safety Measures:''' Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
| '''Class 3''' || May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
<br />
'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers.<br />
<br />
'''Safety Measures:''' Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
<br />
'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers.<br />
<br />
'''Safety Measures:''' Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
'''Safety Measures:''' Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Description<br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || Location: north wall <br />General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || Location: south wall<br />Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Location: ceiling<br />
|-<br />
|Portable extinguishers || Location: north wall and next to the basin<br />
|-<br />
Interlock system || Location: before the main room<br />
|-<br />
|First aid kit || Location: north wall<br />A basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Location: before the main room<br />Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks<br />
|-<br />
|Laser goggles || Location: before the main room<br />
Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || Location: to the right of the main door, inside the laboratory<br />In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door Location: East wall, three-door exit<br />In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
7.2 Electric panels<br />
L2I is equipped with three electrical panels. The main one is Panel 3.<br />
<br />
Panel 1 Panel 2 Panel 3<br />
<br />
The tables below detail the layout of the electrical panels.</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6042Laser Safety Manual2025-03-17T11:45:23Z<p>Ist23437: /* General risk assessment */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|upright=0.5|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
'''Safety Measures:''' No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
'''Safety Measures:''' Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
| '''Class 3''' || May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
<br />
'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers.<br />
<br />
'''Safety Measures:''' Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
<br />
'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers.<br />
<br />
'''Safety Measures:''' Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
'''Safety Measures:''' Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Description<br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || Location: north wall <br />General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || Location: south wall<br />Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Location: ceiling<br />
|-<br />
|Portable extinguishers || Location: north wall and next to the basin<br />
|-<br />
Interlock system || Location: before the main room<br />
|-<br />
|First aid kit || Location: north wall<br />A basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Location: before the main room<br />Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks<br />
|-<br />
|Laser goggles || Location: before the main room<br />
Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || Location: to the right of the main door, inside the laboratory<br />In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door Location: East wall, three-door exit<br />In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
7.2 Electric panels<br />
L2I is equipped with three electrical panels. The main one is Panel 3.<br />
<br />
Panel 1 Panel 2 Panel 3<br />
<br />
The tables below detail the layout of the electrical panels.</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Ficheiro:L2i_crane.png&diff=6041Ficheiro:L2i crane.png2025-03-17T11:44:06Z<p>Ist23437: </p>
<hr />
<div></div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6040Laser Safety Manual2025-03-17T11:41:24Z<p>Ist23437: /* General risk assessment */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
[[Ficheiro:L2i crane.png|miniaturadaimagem|L2I heavy duty (2000 kg) crane.]]<br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
'''Safety Measures:''' No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
'''Safety Measures:''' Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
| '''Class 3''' || May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
<br />
'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers.<br />
<br />
'''Safety Measures:''' Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
<br />
'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers.<br />
<br />
'''Safety Measures:''' Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
'''Safety Measures:''' Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Description<br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || Location: north wall <br />General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || Location: south wall<br />Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Location: ceiling<br />
|-<br />
|Portable extinguishers || Location: north wall and next to the basin<br />
|-<br />
Interlock system || Location: before the main room<br />
|-<br />
|First aid kit || Location: north wall<br />A basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Location: before the main room<br />Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks<br />
|-<br />
|Laser goggles || Location: before the main room<br />
Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || Location: to the right of the main door, inside the laboratory<br />In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door Location: East wall, three-door exit<br />In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
7.2 Electric panels<br />
L2I is equipped with three electrical panels. The main one is Panel 3.<br />
<br />
Panel 1 Panel 2 Panel 3<br />
<br />
The tables below detail the layout of the electrical panels.</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6039Laser Safety Manual2025-03-17T11:25:22Z<p>Ist23437: /* Emergency procedures */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
'''Safety Measures:''' No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
'''Safety Measures:''' Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
| '''Class 3''' || May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
<br />
'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers.<br />
<br />
'''Safety Measures:''' Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
<br />
'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers.<br />
<br />
'''Safety Measures:''' Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
'''Safety Measures:''' Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Description<br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || Location: north wall <br />General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || Location: south wall<br />Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Location: ceiling<br />
|-<br />
|Portable extinguishers || Location: north wall and next to the basin<br />
|-<br />
Interlock system || Location: before the main room<br />
|-<br />
|First aid kit || Location: north wall<br />A basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Location: before the main room<br />Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks<br />
|-<br />
|Laser goggles || Location: before the main room<br />
Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || Location: to the right of the main door, inside the laboratory<br />In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door Location: East wall, three-door exit<br />In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
7.2 Electric panels<br />
L2I is equipped with three electrical panels. The main one is Panel 3.<br />
<br />
Panel 1 Panel 2 Panel 3<br />
<br />
The tables below detail the layout of the electrical panels.</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6038Laser Safety Manual2025-03-17T11:24:54Z<p>Ist23437: /* Emergency procedures */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure for further instructions.<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
<br />
|}<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
'''Safety Measures:''' No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
'''Safety Measures:''' Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
| '''Class 3''' || May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
<br />
'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers.<br />
<br />
'''Safety Measures:''' Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
<br />
'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers.<br />
<br />
'''Safety Measures:''' Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
'''Safety Measures:''' Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Description<br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || Location: north wall <br />General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || Location: south wall<br />Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Location: ceiling<br />
|-<br />
|Portable extinguishers || Location: north wall and next to the basin<br />
|-<br />
Interlock system || Location: before the main room<br />
|-<br />
|First aid kit || Location: north wall<br />A basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Location: before the main room<br />Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks<br />
|-<br />
|Laser goggles || Location: before the main room<br />
Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || Location: to the right of the main door, inside the laboratory<br />In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door Location: East wall, three-door exit<br />In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
7.2 Electric panels<br />
L2I is equipped with three electrical panels. The main one is Panel 3.<br />
<br />
Panel 1 Panel 2 Panel 3<br />
<br />
The tables below detail the layout of the electrical panels.</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Ficheiro:Incendio.png&diff=6037Ficheiro:Incendio.png2025-03-17T11:24:26Z<p>Ist23437: </p>
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<div></div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6036Laser Safety Manual2025-03-17T11:24:04Z<p>Ist23437: /* Emergency procedures */</p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
* See the figure below for further instructions.<br />
|}<br />
<br />
[[Ficheiro:Incendio.png|miniaturadaimagem|Fire emergency procedures. Top: 1) Turn your back against the wind; 2) Aim the jet toward the bottom of the flames; 3) Use several fire extinguishers at once, not one at a time. Bottom: 4) Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. 5) Ensure the fire is completely extinguished to prevent reignition; 6) Notify the Security Central so that used extinguishers can be replaced.]]<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
'''Safety Measures:''' No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
'''Safety Measures:''' Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
| '''Class 3''' || May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
<br />
'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers.<br />
<br />
'''Safety Measures:''' Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
<br />
'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers.<br />
<br />
'''Safety Measures:''' Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
'''Safety Measures:''' Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Description<br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || Location: north wall <br />General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || Location: south wall<br />Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Location: ceiling<br />
|-<br />
|Portable extinguishers || Location: north wall and next to the basin<br />
|-<br />
Interlock system || Location: before the main room<br />
|-<br />
|First aid kit || Location: north wall<br />A basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Location: before the main room<br />Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks<br />
|-<br />
|Laser goggles || Location: before the main room<br />
Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || Location: to the right of the main door, inside the laboratory<br />In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door Location: East wall, three-door exit<br />In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
7.2 Electric panels<br />
L2I is equipped with three electrical panels. The main one is Panel 3.<br />
<br />
Panel 1 Panel 2 Panel 3<br />
<br />
The tables below detail the layout of the electrical panels.</div>Ist23437http://www.mysolutions.tecnico.ulisboa.pt//wiki/index.php?title=Laser_Safety_Manual&diff=6035Laser Safety Manual2025-03-17T11:18:39Z<p>Ist23437: </p>
<hr />
<div>Laboratory workers must be aware of its potential hazards, which can affect people, equipment, and the environment. In particular, safety is of paramount importance in a high-power laser laboratory. A safety manual is a foundational document that ensures the well-being of everyone working within the laboratory environment. <br />
<br />
This document describes the rules, guidelines and protocols that must be followed by the users of the Laboratory for Intense Lasers in order to ensure safe working conditions. Before gaining access to working in the lab, users must be thoroughly familiar with these safety measures and acknowledge their understanding. There are a number of reasons why safety must be strictly implemented:<br />
* by following safety rules, users acquire essential skills that are vital in a laboratory context, including the ability to identify and mitigate risks, correctly use personal protective equipment, handle hazardous materials and equipment safely, and respond effectively to emergency situations<br />
* users are not only protecting themselves from potential hazards but also ensuring the integrity of their scientific work<br />
* familiarity with safety protocols fosters a culture of responsibility and diligence, encouraging conscientious laboratory practices<br />
* the knowledge and skills gained from being aware of and implementing safety measures contribute to the creation of a secure, productive, and harmonious work environment.<br />
<br />
This manual is provided to all current and new users of L2I, including permanent or visiting members, researchers, students, trainees and technical staff. It describes the specific safety and health risks related to working at this laboratory and complements the information available in the general [https://nshs.tecnico.ulisboa.pt/files/sites/10/manual-de-seguranca-para-laboratorios-en.pdf IST Laboratory Safety Manual], the [https://nshs.tecnico.ulisboa.pt/emergencia/ IST NSHS Emergency Procedures] and within the laboratory in the form of Standing Orders, first-aid instructions, fire and earthquake safety procedures or other local safety documentation. <br />
<br />
New laboratory users or anyone planning to operate with lasers, equipment or machinery at L2I must obtain previous permission from the Laboratory Head. This implies that the user fully understands the inherent risks by completing the following three steps:<br />
* reading thoroughly this manual <br />
* completing the laser safety training <br />
* signing the corresponding form<br />
<br />
L2I users are responsible not only for their own safety but also for that of those around them. They must adhere to the active safety measures specific for each situation and ensure that other users also do the same. Any temporary or permanent change to a setup that introduces changes to the current safety protocol must be discussed in advance with the Laboratory Head of Chief Engineer/LSO.<br />
<br />
This document is available in MediaWiki format and will be updated periodically.<br />
<br />
<br />
<br />
=Emergency instructions=<br />
==Contacts==<br />
[[Ficheiro:IST-flagpole.png|miniaturadaimagem|IST Emergency Assembly Point.]]<br />
* European Emergency Number: <span style="color:#FF0000;>'''112'''</span><br />
* IST Security Central: Ext. <span style="color:#FF0000;>'''2000'''</span> or tel. <span style="color:#FF0000;>'''218 418 000'''</span><br />
* Emergency Assembly Point: in front of the Central Pavilion next to the flagpole (see image on the right)<br />
<br />
==Emergency procedures==<br />
The following summary of '''IST emergency instructions''' is intended for use in situations where an immediate danger poses a threat to an individual. All incidents/accidents should be reported to the CE as a mechanism to help preventing their reoccurrence. <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Health or safety emergency''' || <br />
* Sound the alarm by pressing the emergency button and call campus security reporting the incident<br />
* Go to the nearest exit, following the emergency signs<br />
* Do not use the lifts<br />
* Go to the designated assembly point<br />
<br />
|-<br />
| '''Medical emergency''' ||<br />
* In case of a severe personal accident (without loss of consciousness), <span style="background:#FFFF00">immediately call 112</span> (if you are using a landline, dial 0112), informing: your phone number and your precise location; the victim’s condition; procedures already performed. Keep calm while answering the questions.<br />
* Contact campus security and report the accident. If you wish you may ask for a first aider.<br />
* In case of a severe accident (with loss of consciousness), <span style="background:#FFFF00">immediately contact campus security</span>, reporting the accident and its location. A trained AED operator will be sent to your location. Then call 112, reporting the accident as explained above.<br />
* Provide first aid to the victim, as long as you feel capable and without taking unnecessary risks<br />
<br />
|-<br />
| '''Alarm sound''' || Intermittent beep:<br />
* Remain vigilant and take action only if you're properly trained.<br />
* Await further instructions from the security officer, receptionist, or floor manager.<br />
Continuous beep (evacuation alarm):<br />
* Exit the building immediately using the designated evacuation routes shown on the Emergency Floor Plan.<br />
* Listen to and follow the guidance of the evacuation team.<br />
* Walk calmly; do not run and do not use elevators.<br />
* If it's safe, close doors as you leave to contain fire and smoke, but do not lock them. This ensures the floor manager can verify everyone has evacuated and enhances safety.<br />
* Do not return for documents or personal items.<br />
* If you detect smoke in stairwells, notify the security officer or receptionist located near the building exit.<br />
* If corridors are filled with smoke, stay low to the ground to avoid inhaling toxic fumes and gases.<br />
* Proceed to the Emergency Assembly Point<br />
|-<br />
| '''Earthquake''' || Identify the safest places: doorway frames and room corners, under sturdy tables or other solid surfaces<br />
Be aware of the most dangerous places: elevators, near windows or tall furniture like bookshelves, the centre of large open rooms, doorways that are not structurally supported<br />
<br />
''During an earthquake''<br />
<br />
If you are inside a building:<br />
* If it's safe, remain in your current location and seek shelter.<br />
* Keep away from windows, shelves and objects that may fall or shatter<br />
* Stay calm and avoid rushing toward the exits; stairs may be congested<br />
* Never use elevators<br />
<br />
If you are outside a building:<br />
* Stay away from tall buildings and objects that may fall<br />
* Move to an open location<br />
<br />
''After the earthquake''<br />
* Keep calm but remain prepared for aftershocks, which can occur seconds or minutes later<br />
* Exit the building if it is not safe to remain inside<br />
* Never use elevators<br />
* Watch out for hazards such as broken glass and exposed electrical cables. Do not handle metal objects in contact with electrical wiring.<br />
* Do not use open flames; there could be gas leaks or flammable materials.<br />
* Assist any injured people if you are trained and it's safe to do so.<br />
* Do not attempt to remove injured people with fractures unless there are other dangers present. Ask for help.<br />
|-<br />
| '''Fire''' ||If you discover a fire:<br />
* Remain calm, activate the nearest alarm button and contact the Security Central immediately.<br />
* Use the appropriate fire extinguishers to attempt to extinguish the fire. Check the labels for the types of fires they are intended to combat and avoid taking unnecessary risks.<br />
* If you cannot extinguish the fire, or if there is heavy smoke, evacuate the area. Keep low to the ground to minimize smoke inhalation, crawling if necessary.<br />
* If possible, safely turn off the main electrical panel and gas supply and close all windows and doors to help contain the fire.<br />
* Do not use elevators during a fire evacuation.<br />
* Leave the building and head to the Emergency Assembly Point<br />
|}<br />
<br />
<br />
<br />
<br />
Turn your back against the wind Aim the jet toward the bottom of the flames Use several fire extinguishers at once, not one at a time<br />
<br />
Tackle fires that are spreading or dripping by directing the extinguisher from top to bottom. Ensure the fire is completely extinguihsed to prevent reignition<br />
Notify the Security Central so that used extinguishers can be replaced<br />
<br />
==Basic first aid guide==<br />
In the event of a '''personal accident''': <br />
* immediately stop any activities to take care of yourself or to assist others<br />
* make sure that there are no active risks (e.g. the laser is left running) that could cause further accidents. <br />
The table below details how to react to possible personal accidents at L2I, whether to oneself or to others:<br />
<br />
{| class="wikitable"<br />
|-<br />
! In case of !! How to proceed<br />
|-<br />
| '''Light wound''' ||<br />
* Wash your hands thoroughly or use disposable gloves to avoid infection. Rinse the wound under clean, running water to remove dirt or debris. If necessary, use a mild soap around the area to clean it further.<br />
* Clean the area dry with a clean cloth. If needed, apply gentle pressure with a clean bandage, cloth, or sterile gauze to stop any minor bleeding.<br />
* Once the bleeding stops, apply a disinfectant. Cover the wound with a sterile adhesive bandage or gauze pad.<br />
|-<br />
| '''Deep wound''' ||<br />
* Use a clean cloth, sterile gauze, or bandage to apply direct pressure on the wound to control bleeding. If the bleeding soaks through the material, do not remove it; instead, place additional gauze or cloth on top and continue applying pressure.<br />
* Have the injured person lie down and elevate the wounded area (if possible) above heart level to reduce blood flow to the wound.<br />
* <span style="background:#FFFF00">Call 112 for medical assistance</span> (or have someone else make the call) and follow the procedures as directed<br />
* Do not attempt to clean a deep wound, especially if it’s still bleeding heavily. The priority is to stop the bleeding until professional help arrives.<br />
* If the wound involves a limb (such as an arm or leg), keep it immobilized and avoid unnecessary movement to prevent further injury.<br />
* If there is a foreign object embedded in the wound, do not attempt to remove it. Removing it may cause further damage and increase bleeding.<br />
* Wait for medical assistance and continue applying pressure to the wound and monitoring the injured person’s condition.<br />
|-<br />
| '''Thermal or fire burning''' || Assess the severity of the burn:<br />
* First-degree burns: Affect only the outer layer of skin (e.g., redness, mild pain).<br />
* Second- and third degree burns: Affect deeper layers of skin and underlying tissues (e.g., blistering, severe pain).<br />
For minor burns:<br />
* Immediately cool the burn by running cool (not cold) water over the burn for 10–20 minutes. After cooling, cover the burn with a sterile, non-stick bandage or clean cloth. Avoid using adhesive bandages directly on the burn, as they can irritate the skin.<br />
For severe burns: <br />
* <span style="background:#FFFF00">Immediately call for emergency medical assistance (112)</span><br />
* Run cool water over a small area of the burn, but do not cool large areas at once. Cover the burn with a clean, dry cloth or non-stick dressing (such as a sterile gauze pad). Avoid using any ointments, creams, or greasy substances (like butter) on the burn..<br />
<br />
|-<br />
| '''Electric shock''' ||<br />
* Do not touch the person if they are still in contact with the electrical source, as you could also receive a shock. Ensure your own safety before assisting.<br />
* Turn off the electrical source immediately if it is safe to do so:<br />
** Switch off the power supply or unplug the equipment causing the shock.<br />
** If you cannot safely turn off the power, try to move the source away from the person using a non-conductive object such as a wooden broom handle, rubber mat, or plastic item.<br />
* <span style="background:#FFFF00">Call emergency services (112)</span> immediately if the person has been exposed to a high-voltage shock or is unconscious, or if there is any concern about their condition.<br />
|}<br />
<br />
==L2I evacuation procedure==<br />
In the general event of a severe emergency requiring users to evacuate the laboratory, follow these actions:<br />
# Dial 2000 and provide information about the problem.<br />
# Abort all the experiments, shut down the electrical panel, and turn of any active machinery. <br />
# Have everyone leave the room through the emergency exit.<br />
# In the case of a small fire, and only if this procedure doesn’t increase the risks, use the appropriate portable extinguisher.<br />
# Close (but don’t lock) the doors and leave the building, following the evacuation route.<br />
<br />
=Laboratory management structure=<br />
==Management levels==<br />
The Laboratory for Intense Lasers (L2I) is dedicated to the study of laser-matter interaction at very high optical powers and is operated by the [https://golp.tecnico.ulisboa.pt/wp/ Group for Lasers and Plasmas] of [https://www.ipfn.tecnico.ulisboa.pt/ IPFN]. The main research areas are laser science and technology, nonlinear optics, plasma physics, high harmonic generation, diode-pumped lasers and optical parametric amplification. L2I is a fundamental stepping-stone in the preparation of high-intensity experiments to be carried out at large-scale facilities, while also playing an important role in the advanced training of young researchers and technological development. Since 2013, L2I is a member of the [https://www.fct.pt/wp-content/uploads/2022/06/Portuguese_Roadmap_Infrastructures2020.pdf National Roadmap of Strategic Research Infrastructures].<br />
<br />
The Group for Lasers and Plasmas (GoLP), is part of the Instituto de Plasmas e Fusão Nuclear at IST. Their activity is focused on the study, both theoretical and experimental, of laser-plasma interactions and other phenomena associated with the interaction of high intensities with plasmas. <br />
<br />
Instituto de Plasmas e Fusão Nuclear (IPFN, Institute for Plasmas and Nuclear Fusion) is a research unit of Instituto Superior Técnico (IST) with the status of Associated Laboratory granted by Fundação para a Ciência e a Tecnologia. IPFN ensures the Portuguese participation in EUROFusion, the European Consortium for the Development of Fusion Energy. Research at IPFN is organized into two thematic areas: controlled nuclear fusion and intense lasers and plasma technologies.<br />
<br />
==Management roles==<br />
The management roles at L2I meets the requirements necessary for a laboratory of its magnitude and consists of the following levels:<br />
<br />
{| class="wikitable"<br />
! Role !! Management responsibilities related to safety<br />
|-<br />
| '''Laboratory Head (LH)''' || <br />
* Proposing and managing all the laboratory activities at the levels of research plan, equipment, acquisitions, activities and human resources.<br />
* Representing the laboratory within IST <br />
* Developing and approving safety policies and operating procedures<br />
* Ensure lab safety protocols are followed and conduct regular safety audits<br />
<br />
|-<br />
| '''Chief Engineer /<br /> Laser Security Officer (CE/LSO''') ||<br />
* Oversee safety compliance and training for all personnel<br />
* Ensuring that all requirements are met prior to conducting experiments.<br />
* Evaluating laser hazards according to the laser classification and determining adequate control measures<br />
* Elaborating documentation relative to laser safety and protective equipment (e.g. eyewear, clothing, gloves, screens, etc.)<br />
* Ensuring that protective equipment is operational<br />
* Developing and overseeing laser safety training<br />
* Reviewing applications for new laboratory users<br />
* Assist in developing safety policies and operating procedures<br />
* Reviewing results of inspections and reports related to safety, incidents or accidents and ensuring their follow-up<br />
|-<br />
| '''Laser Users (LU)''' ||<br />
* Complete the laser safety training before working in the laboratory<br />
* Complying with all the safety measures in place<br />
* Conducting all laser activities in accordance with accepted laboratory safety practices<br />
* Wearing appropriate laser eye protection<br />
* Reporting any unsafe practices or usage of lasers to the LH or CE/LSO.<br />
|}<br />
<br />
<br />
As of 2025 the management roles are as follows:<br />
* Laboratory Head: Gonçalo Figueira, Hugo Pires (deputy)<br />
* Chief Engineer: Jessica Diaz, Gonçalo Figueira (deputy)<br />
<br />
==User levels==<br />
At L2I system of controlled access through an ID card system (the same as for restricted access within IST) is in place. Entrance authorizations for L2I are issued by the CE upon request and depend on the context of the visit. The following categories of access are in place:<br />
{| class="wikitable"<br />
|-<br />
| '''Independent access''' || <br />
* Permanent faculty and staff, PhD students, post-doc researchers doing laser-related work<br />
* Requires completion of laser training<br />
|-<br />
| '''Accompanied access''' || <br />
* Undergraduate students doing laser-related work, except under limited circumstances<br />
* Visiting researchers and collaborators performing short-term experiments<br />
* Requires completion of laser training<br />
<br />
|-<br />
| '''Short term visitors''' || <br />
* External individuals or groups e.g. schools<br />
* Suppliers and contractors <br />
* Visitors must be accompanied at all times by a member with Independent Access category<br />
<br />
|}<br />
<br />
=Safety risks in the laboratory=<br />
==General risk assessment==<br />
The list below describes the main hazards present in L2I. In this manual, particular attention is dedicated to laser risks (see next chapter), due to their specific characteristics.<br />
<br />
{| class="wikitable"<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Chemical_hazard Chemical]''' || <br />
* Compressed gases, including helium and hydrogen and high gas pressures<br />
* Flammable liquids, including solvents and alcohol<br />
* Oil exhaustion from vacuum pumps<br />
* Vapours and fumes from laser ablation<br />
|-<br />
| '''[https://en.wikipedia.org/wiki/Ergonomic_hazard Ergonomic]''' || <br />
* Standing up for prolonged periods<br />
* Back risk due to bending over large optical tables<br />
* Moving or transporting heavy objects<br />
|-<br />
| '''Physical''' || <br />
* [https://en.wikipedia.org/wiki/Fire_safety Fire]<br />
* [https://en.wikipedia.org/wiki/Laser_safety Laser exposure] (high power / high energy / visible and infrared) with potentially serious eye or skin injury<br />
* [https://en.wikipedia.org/wiki/Occupational_noise High level noises]<br />
* [https://en.wikipedia.org/wiki/Occupational_hazard#Heat_and_cold_stress Cold temperature and low humidity]<br />
* Compressed air<br />
* [https://en.wikipedia.org/wiki/Falling_(accident) Falling] from heights, including ladders and elevated work areas<br />
|-<br />
| '''Safety''' || <br />
* Hard surfaces<br />
* [https://en.wikipedia.org/wiki/Electrical_injury Electrical hazards], including high voltage<br />
* Confined or blocked spaces<br />
* [https://en.wikipedia.org/wiki/Lifting_equipment Lifting] heavy objects using the crane<br />
* Tripping and slipping (objects or cords across the floor)<br />
* Moving machinery parts<br />
* Water leaks and floods<br />
|}<br />
<br />
==Chemical risks==<br />
===Compressed gases and high gas pressures===<br />
Several compressed gases are commonly used in the laboratory. They present a number of hazards for the laboratory user: <br />
* Gas cylinders may contain gases that are flammable, toxic, corrosive, asphyxiants, or oxidizers. <br />
* Unsecured cylinders can be easily knocked over, causing serious injury and damage. <br />
* Impact can shear the valve from an uncapped cylinder, causing a catastrophic release of pressure leading to personal injury and extensive damage. <br />
* Mechanical failure of the cylinder, cylinder valve, or regulator can result in rapid diffusion of the pressurized contents of the cylinder into the atmosphere.<br />
It is fundamental that compressed gases are properly handled:<br />
* Gas bottles must be clearly identified in a visible location.<br />
* The laboratory location is incompatible with gases that can become dangerous through accumulation. These must be installed in a properly ventilated area outside.<br />
* In the event that a dangerous gas must be temporarily present in the laboratory, adequate gas detectors must be installed to monitor for leaks.<br />
* Ensure gas cylinders are stored upright and secured to prevent tipping over. See the section on ergonomic risks for the procedures related to gas bottle transportation.<br />
When transporting gas cylinders:<br />
* Always use a heavy duty hand truck equipped with a chain or belt for securing the cylinder.<br />
* Make sure the protective cap is covering the cylinder valve.<br />
* Never transport a cylinder while a regulator is attached.<br />
* Always use caution when transporting cylinders – they are heavy and can easily tip over.<br />
* Do not move compressed gas cylinders by carrying, rolling, sliding, or dragging them across the floor.<br />
* Do not transport oxygen and combustible gases at the same time.<br />
* Do not drop cylinders or permit them to strike anything violently.<br />
Safe storage of compressed gas cylinders:<br />
* Only the minimum essential number of cylinders must be inside the laboratory at any time<br />
* Cylinders must be secured to the wall to prevent them from falling over. <br />
* Cylinders should be stored away from heat, from areas where they might be subjected to mechanical damage or an electrical discharge.<br />
* The protective cap should always be left on the cylinder when it is not in use. The cap keeps the main cylinder valve from being damaged or broken.<br />
Safe operation of compressed gas cylinders:<br />
* Make sure that the cylinder is secured.<br />
* Attach the proper regulator to the cylinder. If the regulator does not fit, it may not be suitable for the gas you are using.<br />
* Attach the appropriate hose connections to the flow control valve. Secure any tubing with clamps so that it will not whip around when pressure is turned on.<br />
* To prevent a surge of pressure, turn the delivery pressure adjusting screw counterclockwise until it turns freely and then close the flow control valve.<br />
* Slowly open the cylinder valve hand wheel until the cylinder pressure gauge reads the cylinder pressure.<br />
* With the flow control valve closed, turn the delivery pressure screw clockwise until the delivery pressure gauge reads the desired pressure.<br />
* Adjust the gas flow to the system by using the flow control valve or another flow control device between the regulator and the experiment.<br />
* After an experiment is completed, turn the cylinder valve off first, and then allow gas to flow from the regulator. When both gauges read “zero”, remove the regulator and replace the protective cap on the cylinder head.<br />
* When a cylinder is close to empty, notify your supervisor that a new cylinder should be ordered.<br />
* When the cylinder is empty, mark it as “Empty”, and store it separate from full cylinders. <br />
Hazards of specific gases:<br />
Inert gases (e.g. Helium, Argon, Nitrogen) – These gases can cause asphyxiation by displacing the air necessary to support life.<br />
Flammable Gases (e.g. Methane, Propane, Hydrogen, Acetylene) – These gases present serious fire and explosion hazards. Do not store near open flames or other sources of ignition. Flammable gases are easily ignited by heat, sparks, or flames, and may form explosive mixtures with air. Vapors from liquefied gas often are heavier than air and may spread along ground and travel to a source of ignition and result in a flashback fire. <br />
<br />
{| class="wikitable"<br />
! Gas !! Cylinder color<br />
|-<br />
| Argon (Ar) || Dark green<br />
|-<br />
| Nitrogen (N2) || Black<br />
|-<br />
| Hydrogen (H2) || Red<br />
|-<br />
| Helium (He) || Brown<br />
|}<br />
<br />
===Flammable liquids, including solvents and alcohol===<br />
[[Ficheiro:chemicals-labels.png|miniaturadaimagem|Safety labels of the cleaning reagents used in the laboratory.]]<br />
At the laboratory there are small amounts of liquid chemicals (see figure with safety labels), mainly used for cleaning optical or mechanical surfaces. The following instructions must be followed when storing and handling these liquids.<br />
* All flammable liquids must be stored in approved containers with appropriate labels and stored in cabinets away from heat sources.<br />
* When not in use, containers must remain tightly sealed to prevent the release of flammable vapours.<br />
* When handling these liquids, always use gloves and work in areas with proper ventilation to disperse flammable vapours. <br />
* Work away from all sources of ignition, such as laser beams, electrical equipment, and hot surfaces. <br />
* Clean any spills immediately using appropriate cleaning materials.<br />
* If working with large quantities, consider using a face shield and a respiratory mask to avoid inhaling harmful vapours.<br />
<br />
===Oil exhaustion from vacuum pumps===<br />
Oil-based vacuum pumps, such as rotary pumps, rely on the oil to lubricate, seal, and cool the internal components. As the pump is used, this oil is slowly exhausted to the atmosphere. To avoid contamination, ensure adherence to the following rules.<br />
* Install oil mist filters or exhaust filters on vacuum pumps to capture oil vapours and prevent them from being released into the atmosphere. Regularly check and replace these filters as part of the pump maintenance schedule, as saturated filters can lose efficiency and allow oil to escape.<br />
* Connect the pump exhaust to the ventilation tubing that directs the exhaust outside the work area.<br />
* Always use the manufacturer-recommended oil. Different pumps require specific oil formulations to ensure optimal performance and minimal exhaust.<br />
* Regularly check the oil level in the pump and ensure that it stays within the recommended range. Low oil levels can cause increased vaporization and inefficient operation, while overfilling can lead to excessive oil mist generation.<br />
* Pump oil must be replaced regularly as per the pump manufacturer's guidelines. Old or contaminated oil can degrade, leading to increased exhaust emissions and poor pump performance.<br />
<br />
===Vapours and fumes from laser ablation===<br />
Laser ablation is a process where material is removed from a solid surface by irradiating it with a laser. This process can produce potentially hazardous vapours, fumes, and particulates, especially when working with metals, polymers, or other chemicals. For instance, metals can release toxic metallic fumes, polymers and plastics can release harmful organic compounds and coated surfaces or paints may release hazardous by-products, including volatile organic compounds and metal oxides. L2I is not designed to handle large amounts of vapours and fumes, and any such experiment must be preceded by a detailed study and risk assessment. Below are some directions to consider.<br />
* Local exhaust ventilation or fume hoods should be in place to prevent the accumulation of hazardous vapours.<br />
* Ensure that the extraction system is equipped with appropriate filters to capture particulate matter and chemical fumes.<br />
* Maintain a well-ventilated work environment, with air circulation systems to prevent the build-up of toxic fumes in confined spaces.<br />
* Wear appropriate respiratory protection in situations where there is a risk of inhaling toxic particles or vapours.<br />
<br />
==Ergonomic risks==<br />
===Standing up for prolonged periods===<br />
Standing up for prolonged periods can pose significant risks to both physical health and overall comfort. Below are some recommended guidelines and practices to address this issue.<br />
* Shift weight and change posture frequently; for instance, alternate between sitting and standing periods, if possible, to avoid constant strain on specific muscle groups.<br />
* Take periodic rest breaks: for every hour of standing, aim for a 5-10 minute break<br />
* Adjust the height of your workstation to prevent bending forward or raising arms unnecessarily.<br />
* If possible, rotate tasks among users to ensure they aren't required to stand for extended periods without relief.<br />
<br />
===Back risk due to bending over large optical tables===<br />
Bending over large optical tables or other experimental setups can pose significant risks to the back, particularly over time, due to the awkward posture required to reach equipment or perform precision tasks. Prolonged or repetitive bending can strain muscles and joints, leading to discomfort, injury, and chronic pain. To mitigate these risks, here are some recommended guidelines and practices:<br />
* Use elevated platforms or steps to bring you to the appropriate height, so that you do not have to bend over the table.<br />
* Break up tasks that require bending by alternating with tasks that allow you to stand upright or sit.<br />
* If objects or equipment on the optical table are heavy or awkward to handle, ask for help to avoid straining the back.<br />
* Arrange the equipment and tools on the optical table so that frequently used items are within easy reach, reducing the need for excessive reaching and bending.<br />
* Keep the workspace organized and free of clutter to minimize unnecessary movements that could lead to strain.<br />
<br />
===Moving or transporting heavy objects===<br />
[[Ficheiro:Lifting-technique.png|miniaturadaimagem|Proper lifting technique for heavy objects requires directing the effort through the legs rather than the back.]]<br />
Occasionally there may be a need to move, lift and/or transport heavy objects, such as laser system components, within the lab or to/from the exterior. The most important rule when handling heavy objects is to have someone helping you. The following safety guidelines will help you to avoid injuries, particularly to the back, shoulders, and legs.<br />
* Evaluate the weight and size of the object before lifting. If the object is too heavy to lift comfortably, use mechanical aids or seek assistance from a co-worker.<br />
* Ensure the path is clear of obstacles and plan the route before moving the object to avoid sudden movements or slips.<br />
* If raising the load using your arms, bend at your knees – not your waist – and keep your back straight. Squat down and use your legs to lift the load, keeping the object close to your body (see figure).<br />
* Avoid twisting your torso while lifting. Instead, turn your entire body by pivoting your feet to prevent back strain.<br />
* Keep the load close to your centre of gravity (near your waist), which minimizes the strain on your back and upper body.<br />
* Use dollies, carts, forklifts, or hand trucks whenever possible to move heavy objects. This reduces the physical strain on your body and minimizes the risk of injury.<br />
* Ensure that any equipment used is appropriate for the load size and weight and that you know how to operate it safely.<br />
* If the object is too heavy or awkward to lift alone, enlist help from one or more co-workers. Coordinate the lift by counting down and lifting at the same time.<br />
* Ensure that all team members use proper lifting techniques and are on the same page regarding the movement plan.<br />
* Wear proper gloves when handling rough equipment (e.g. wooden crates) to avoid skin abrasion.<br />
<br />
==Physical risks==<br />
===Fire===<br />
See section [[Laser_Safety_Manual#Emergency_procedures|Emergency procedures]].<br />
<br />
===Laser exposure with potentially serious eye or skin injury===<br />
See section [[Laser_Safety_Manual#Laser_safety|Laser safety]].<br />
<br />
===High level noises===<br />
When working at L2I there are several sources producing continuous noise that can be bothersome after long hours of exposure. These include the Air Treatment Unit (ATU), chillers (air-cooled and water-cooled), fans and other noisy equipment. Continuous exposure to noise can lead to stress, fatigue, and other physical effects. Here are safety measures and practices for dealing with noisy environments:<br />
* If you feel bothered by the noise level, consider wearing earplugs or earmuffs. Balance their use with the need of remaining aware to other risks in the laboratory, e.g. alarm sounds.<br />
* Ensure that all noisy machinery is properly closed (e.g. the ATU doors)<br />
* Take frequent rests and go outside the laboratory for a few minutes.<br />
<br />
===Cold temperature and low humidity===<br />
L2I is a Class 10,000 clean room with a temperature setting of around 20.0 degrees and humidity setting of around 40%. Working in this type of environment presents specific challenges that can affect both comfort and performance. <br />
* When planning to work in the lab, choose clothing that provides good thermal insulation to prevent body heat loss.<br />
* Schedule regular breaks in warmer environments to regulate your body temperature and avoid discomfort.<br />
* Low humidity environments can lead to dehydration and dry skin. Drink water regularly to maintain hydration.<br />
<br />
===Compressed air===<br />
Compressed air is available in the laboratory for different uses. While it is a versatile tool, it poses several safety risks if not handled properly.<br />
* Do not use compressed air to clean skin, clothes, or surfaces where people may come into contact with the air. The high-pressure air can penetrate the skin, causing serious injuries, and dislodge particles that can damage eyes or be inhaled.<br />
* Never point a compressed air nozzle at yourself or others, as this can result in serious injuries. Even low-pressure air can be dangerous when directed at a person's body.<br />
* Always wear safety goggles or a face shield when using compressed air to prevent debris from being blown into your eyes.<br />
* Keep compressed air at a safe working pressure for the task at hand.<br />
* When using air tools, make sure they are properly secured to avoid them becoming projectiles due to the force of compressed air.<br />
* The compressed air cylinders should be stored properly and kept them away from heat sources or sparks.<br />
<br />
===Falling from heights, including ladders and elevated work areas===<br />
Falling from heights, ladders, or elevated work areas, is a serious safety hazard that must not be dismissed. At L2I the need to work at a height may arise e.g. from climbing onto tables or others heavy furniture to assemble setups, cabling, curtains, etc. Electrical maintenance should be performed by specialised technicians only.<br />
* Ensure that ladders are in good condition, appropriately rated for the weight load, and placed on stable ground.<br />
* Maintain 3 points of contact (two hands and one foot, or two feet and one hand) when climbing.<br />
* Always face the ladder when climbing up or down and use both hands for stability.<br />
* Do not stand on the top rungs or overreach; reposition the ladder if needed.<br />
* Plan the task to minimize time spent working at heights. Where possible, perform tasks on the ground or use equipment to bring the work area to a safer level.<br />
* Keep tools and materials secured to prevent them from falling and causing injury to others below.<br />
<br />
==Safety risks==<br />
===Hard surfaces===<br />
[[Ficheiro:foam-impact.png|miniaturadaimagem|Using yellow-black foam for impact protection.]]<br />
Virtually all the work surfaces at L2I are hard, which can lead to head or facial injuries from accidental contact or impact.<br />
* Mark overhead obstacles and protruding objects at head height with bright (e.g. yellow or black/yellow tape) or warning signs to ensure they are easily noticeable.<br />
* Use padding or cushioning materials to cover hard surfaces that could pose a risk of head impact to soften any accidental contact. For instance, bubble wrap or impact foam can be used for this (see figure).<br />
* In a situation of potential head injury, e.g. working under an optical table, wear a hard hat.<br />
* Where possible, relocate or modify hard surfaces at head level to reduce the risk of injury. For example, adjust shelving, overhead storage, or equipment to minimize contact with head-level surfaces.<br />
* Ensure that walkways and workstations are designed to avoid head-level hazards. Clear paths of low-hanging obstacles and ensure enough clearance for users to move safely.<br />
* Always use adequate lighting to ensure that you can see obstacles clearly.<br />
<br />
===Electrical hazards, including high voltage===<br />
[[Ficheiro:cable-cover.png|miniaturadaimagem|Rubber cable cover for cable protection.]]<br />
At L2I there is a large amount of electrical equipment, including high voltage equipment. Although electrical circuits are mostly confined to these devices, on some occasions users may have to install electrical circuits in the setups. The use of high voltage outside professional equipment should only be done under the assistance of an electrical technician. To address electrical hazards, it's crucial to follow comprehensive safety guidelines.<br />
* Identify high voltage areas: clearly mark and label areas where high-voltage (>600 V) equipment is present. Use warning signs such as "Danger – High Voltage."<br />
* Insulation and barriers: High-voltage cables and equipment should be properly insulated and enclosed to prevent accidental contact. Ensure barriers or physical guards are in place where necessary.<br />
* Avoid placing electrical cables in high-traffic areas to reduce the risk of tripping and damage. If unavoidable, use rubber cable covers (see figure) to protect both cables and people.<br />
* Neither cables nor electrical equipment should not be laid in areas prone to water accumulation (e.g. near the ATU or the water basin) to avoid electrical shock hazards.<br />
* Whenever possible, run cables along walls or optical tables using cable trays or conduits.<br />
* Keep cables away from sharp objects or edges that could cause damage or fraying of the insulation.<br />
* Check cords for damage or wear, especially at the plugs and along the insulation before each use. Any cables compromised with cuts or damage should be disconnected and replaced immediately.<br />
* Avoid plugging too many high-wattage devices into a single outlet. Use power strips with surge protectors to distribute electrical load evenly, but even those should not be overloaded. Never use multi-plug adapters instead of power strips.<br />
* Do not overload extension cords or daisy-chain them together. Overloaded cords can lead to overheating and fire hazards.<br />
* All electrical equipment and systems should be properly grounded to prevent the risk of electric shock.<br />
* Label all electric cords with a description of the device they are connected to. This saves time when solving problems.<br />
* Never handle electrical equipment with wet hands.<br />
<br />
===Confined or blocked spaces===<br />
Confined or blocked spaces, such as when working in a tight space between a large optical table and a wall or under an optical table, pose significant risks. A confined space is typically an area not designed for continuous occupancy and with limited access. Working in such a space should be considered only as an exceptional circumstance. Experimental setups that require a user to stay in a confined space must be absolutely avoided. A blocked space can also result from an improperly placed large object obstructing the passage, namely preventing a user from reaching the emergency exit in a swift manner. This type of action is only acceptable during exceptional maintenance and for periods as short as possible.<br />
* Remove obstacles that could block the passage or access to any point in the laboratory. Ensure a clear path for entry and exit to prevent users from being trapped or hindered in emergencies.<br />
* Plan tasks efficiently to minimize the time spent in tight or blocked spaces. <br />
* If blockages are unavoidable due to equipment or maintenance, schedule tasks to remove or rearrange objects regularly to keep the space safe and accessible.<br />
* Avoid working in confined or blocked spaces when alone in the laboratory.<br />
<br />
===Lifting heavy objects using the crane===<br />
L2I is equipped with a crane capable of lifting heavy objects up to 2000 kg. If you don’t know how to operate the crane, ask for assistance. Do not try to operate it yourself as this can pose significant risks, both personal (e.g. being trapped under a heavy load) and to the equipment.<br />
* You should preferably use the crane when someone else is in the laboratory.<br />
* Assess the load: Determine the weight and dimensions of the object to be lifted. Ensure that the crane’s lifting capacity, as well as the rigging equipment (cables, shackles, etc), are suitable for the load, and that all rigging equipment (slings, shackles, etc.)<br />
* Review the lift plan with everyone involved. This includes determining the safest path of travel and identifying potential obstacles.<br />
* Ensure the load is properly balanced and secured before lifting. Use appropriate rigging to avoid slippage, tilting, or shifting during the lift.<br />
* Wear a hard helmet and safety gloves. Never stand under the load, in any circumstances.<br />
* The L2I crane has two speeds. Always lift and lower the load using low speed and steadily to avoid sudden movements that could cause the load to swing or shift. The fast speed should only be used when the lead is clear from surrounding objects and persons.<br />
* Displace the load slowly and using the auxiliary chain. Do not pull the load directly.<br />
* The crane has a specific maintenance plan. Warn the CE in case anything seems out of order.<br />
<br />
===Tripping and slipping===<br />
This risk is related to confined or blocked spaces, but also includes smaller obstacles that, while not preventing the passage, may lead to the user tripping and falling. For obvious reasons, this may lead to significant physical injury. Leaving objects lying on pathways is a severe violation of workplace safety that must be avoided. This includes e.g. backpacks, bags, tools, steps, boxes, computers and other equipment, cables and anything that prevents the user from walking safely.<br />
* Ensure that all paths are free of clutter such as personal items, equipment, boxes, or other objects that could cause tripping.<br />
* Avoid leaving loose objects on the floor, such as tools, materials, or waste.<br />
* Use cable management systems, such as cable covers to keep cords organized and off the floor.<br />
* In pathways, ensure that any cords crossing the floor are properly secured with cable covers to prevent tripping hazards. Cables should never be left loose or stretched across high-traffic areas without proper protection.<br />
* If cords cannot be removed from a walkway, they should be raised above floor level or rerouted along walls or ceilings to eliminate the tripping risk.<br />
* Any spills should be cleaned up immediately.<br />
* The floor at L2I is marked with a fluorescent tape on the floor to guide you to the exit in the event of a power failure.<br />
<br />
===Water leaks and floods===<br />
Although L2I is equipped with a water drain, next to the basin, unexpected floods can happen as a result of water leaks, defective tubing or machinery malfunction (e.g. the ATU). A flood in a laboratory can quickly become a major source of damage to equipment unless a set of rules is strictly adhered to.<br />
* Water leaks and floods in workplaces, homes, or industrial settings can lead to significant damage and safety hazards, including electrical risks, structural damage, mold growth, and slip-and-fall injuries. Addressing these risks requires a combination of preventive measures and emergency response procedures. Below are essential guidelines to handle and prevent water leaks and floods:<br />
* In case you identify any water-related issue, e.g. a dripping tube, pools of water o the floor, accumulation of droplets, signs of corrosion etc that could lead to larger water leaks, immediately notify the CE.<br />
* Keep the water drain unobstructed and periodically check its cleanliness.<br />
* Avoid placing electrical objects on the floor, instead placing them on the tables, overhead shelves or elevated on solid blocks.<br />
In the event of a significant water leak or flood:<br />
* Immediately notify the Security Central and ask them to turn off the water supply (located outside the laboratory).<br />
* Turn off electrical power to the affected areas to prevent electrocution or fire hazards, especially if water comes into contact with electrical outlets or appliances. <br />
* Avoid entering flooded areas where electrical outlets, devices, or wires are submerged until the power has been safely disconnected.<br />
* Open the laboratory doors to avoid rising water levels.<br />
* Evaluate the extent of the possible damage: unless you think that you can manage the flood until help arrives, do not stay in the laboratory. <br />
* After the water is removed, ensure that affected areas are thoroughly dried out.<br />
<br />
==Other rules and work practices==<br />
===Cleanroom rules===<br />
The entire laboratory space is a certified Class 10,000 clean room. Specific cleanliness measures are in place to ensure that this status is met consistently, and the laboratory is maintained free of dust and contaminants. In particular, users must actively ensure that the rules below are followed at all times.<br />
* Before entering the main laboratory hall or the upper floor, users must wear a lab coat, shoe covers and a hair net. For work involving the handling of delicate optical surfaces, latex gloves must be worn. These items are available at the entrance to the main hall.<br />
* Personal items such as coats or other clothing, bags, and backpacks must be left outside the main hall. A small table with decks and a rail with coat hangers are available.<br />
* Items made of particulate-generating materials are non-cleanroom compatible and must be left outside the lab. This includes cardboard or wood boxes, uncleaned or corroded metal, oily or dusty surfaces, and fabrics such as wool.<br />
* The main door should be kept open for only the minimum time required. A loud beeping sound is heard while the door is open to remind users of this.<br />
* Inside the clean room, avoid movements or actions that could create turbulence in the air, such as fast motions or making wide movements. Inspect large surfaces for dirt before moving them and clean them if needed.<br />
* Ensure that the working surfaces are left clean and tidy after completing your work. Dispose of waste materials in the designated containers. <br />
* Do not obstruct the clean room filtration systems.<br />
* Notify the CE in case any abnormal accumulation of dust is detected.<br />
<br />
===Workplace rules===<br />
* Return of equipment and tools: at the end of each lab session, ensure that all common equipment, instruments, and tools are returned to their designated locations. This is essential to prevent delays and confusion for other users."<br />
* Working area clean-up: always clean your workstation after use and properly dispose of all waste materials in the appropriate bins.<br />
* Taking equipment outside the lab: removing equipment, tools, or components from the lab without explicit written authorization from the Lab Head (LH) or Chief Engineer (CE) is strictly prohibited. Any requests to take items out of the lab must be submitted in writing, detailing the specific items, their destination, and the expected duration of removal.<br />
* Personal Protective Equipment: Ensure that all required PPE is worn during lab activities and that PPE is returned to its designated storage location after use.<br />
* Reporting incidents: report any damaged equipment, spills, or incidents immediately to the CE or LH to ensure prompt resolution and maintain a safe working environment.<br />
* Respect for shared spaces: be mindful of shared spaces and resources. Avoid monopolizing equipment for extended periods and communicate with others to ensure smooth lab operations.<br />
<br />
===Working hours===<br />
As a general rule, due to the location, restricted access and general risks present in the laboratory, working accompanied is strongly recommended, in particular when using the high-power laser systems. If absolutely required, a user may stay alone in the lab for a limited time, in which case the following protocol must be followed:<br />
* the user formally notifies a colleague, the CE or the LH of their intentions and makes sure that the message was received.<br />
* after finishing the work session, the user again contacts the said person to confirm that he/she has left the lab; failure to do so may trigger an emergency warning due to absence of contact.<br />
Plans for foreseeable and repeated periods of working alone must be discussed with the LH or the CE.<br />
<br />
<br />
=Laser safety=<br />
Adequate laser safety measures are essential to protect individuals, equipment, and the environment from potential hazards associated with laser use. High-power lasers can cause severe injuries, including eye and skin damage, as well as fire hazards and material degradation. Implementing safety protocols, such as using appropriate protective eyewear, controlling beam exposure, and enforcing access restrictions, minimizes risks and ensures a safe working environment. Additionally, adherence to safety regulations and best practices not only prevents accidents but also promotes responsible use of laser technology in research, industry, and medical applications. A well-informed and safety-conscious approach is crucial to maintaining both operational efficiency and the well-being of all personnel.<br />
<br />
==Training==<br />
L2I hosts several laser systems with a wide range of parameters. Up to date information is available on the internal web pages and in the form of Standing Orders before entering the main hall. Laser safety training is mandatory for all prospective users. This consists of individual study and accompanied access to the L2I lasers. <br />
<br />
'''Individual study''' is done through reading materials (including, but not limited to, the present manual) and videos, and aims at acquiring a thorough knowledge of the following concepts:<br />
* Classification of lasers and laser systems: wavelengths, CW/pulsed, energy, power, exposure <br />
* General laser safety principles: personal protective equipment, control measures<br />
* Effects of laser radiation on the human body and emergency procedures<br />
<br />
'''Accompanied access''' consists of a predetermined number of initial sessions in the laboratory during which the used acquires practical training in the safety measures and operation of the laser systems, supervised by a registered user. The emission of independent access status depends on the positive evaluation concerning the understanding and adherence to safety measures.<br />
<br />
==Guest visits==<br />
Guest visits to the lab may occur with short notice and can include colleagues, visitors, students, journalists, or other external parties. To accommodate these visits smoothly and safely, the following guidelines must be followed:<br />
* The visit must be scheduled as soon as possible with both the current lab users and the CE to avoid disruptions to ongoing experiments and ensure proper preparation. The corresponding slot must be reserved in the team's calendar.<br />
* During the entire duration of the visit, all laser systems must be either powered down or securely blocked to prevent accidental exposure. No active laser beams are allowed.<br />
* Guests are required to wear cleanroom PPE. Prior to the visit, they should be given a brief orientation to ensure they understand and comply with cleanroom protocols.<br />
* Guests must be supervised at all times during their visit by lab personnel to ensure compliance with safety standards and prevent unauthorized handling of equipment.<br />
<br />
==Classification of lasers and laser systems==<br />
Lasers are classified into four main safety classes based on their potential risk to human eyes and skin, as detailed in the tables below. The first table provides a quick summary of laser classes and the second one details the specific considerations within each class.<br />
<br />
{| class="wikitable"<br />
! Laser class !! Risk level !! Precautions<br />
|-<br />
| '''Class 1''' ||Minimal || No special precautions<br />
|-<br />
| '''Class 2''' || Low || Avoid staring into the beam<br />
|-<br />
| '''Class 3''' || Moderate || Use protective eyewear and barriers<br />
|-<br />
| '''Class 4''' || High || Full enclosure, protective eyewear, no direct exposure<br />
|}<br />
<br />
<br />
{| class="wikitable" <br />
|style="width: 10%"| '''Class 1''' || These lasers are considered safe under all conditions of normal use. The output power is low enough that it poses no hazard, even with prolonged exposure. Example: laser printers.<br />
'''Safety Measures:''' No specific safety precautions are required, but it is important to ensure the laser is used as intended and remains properly enclosed.<br />
|-<br />
| '''Class 1M''' || Similar to Class 1, but potentially hazardous if viewed with through magnifying optical aids such as magnifying lenses or binoculars.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam, and ensure the laser remains enclosed. Proper warning labels should be in place <br />
|-<br />
| '''Class 2''' || These are visible lasers (wavelengths 400–700 nm) with low power, typically under 1 mW. They are safe for short accidental exposure due to the blink reflex. Example: laser pointers.<br />
'''Safety Measures:''' Do not intentionally stare into the beam. Warn others about the laser, label the device clearly, and avoid directing it at people.<br />
|-<br />
| '''Class 2M''' || Like Class 2 but can be dangerous when viewed with optical instruments.<br />
'''Safety Measures:''' Avoid using magnifying devices to view the beam. Post warning signs and instruct users not to point the laser at people.<br />
|-<br />
| '''Class 3''' || May be hazardous under direct and specular reflection viewing conditions but is normally not a diffuse reflection or fire hazard. There are two subclasses:<br />
<br />
'''Class 3R''' lasers are more powerful (up to 5 mW) and can be hazardous if viewed directly for extended periods but are generally safe with brief exposure. Example: some laser pointers.<br />
<br />
'''Safety Measures:''' Direct exposure to the eyes should be avoided. Label the device properly, use warning signs, and limit access to trained users. Example: higher-power laser pointers.<br />
<br />
'''Class 3B''' lasers can cause serious eye injury from direct or specular reflection exposure. Skin injury is less likely but possible. Example: industrial and research lasers.<br />
<br />
'''Safety Measures:''' Eye protection designed for the specific laser wavelength is essential. Never look directly at the beam or its reflections. Enclose the laser beam path where possible, post clear warning signs, and restrict access to trained personnel.<br />
|-<br />
| '''Class 4''' || These are the most hazardous lasers, capable of causing severe eye and skin injuries. They also pose a fire hazard. Direct, scattered, or reflected beams from these lasers are dangerous. Examples: cutting, welding, or medical lasers.<br />
<br />
'''Safety Measures:''' Use protective eyewear and clothing designed for the laser's wavelength and power. Enclose the laser and the beam as much as possible, employ interlock systems, post visible warning signs, and restrict access to a controlled area. Use laser safety curtains or shields to contain reflections.<br />
<br />
|}<br />
<br />
==Laser safety: main parameters==<br />
===Laser hazards vs. wavelength range===<br />
Concerning ocular hazards, the potential damage caused by laser radiation to the eyes is strongly dependent on its wavelength region:<br />
<br />
'''Ultraviolet light''' (<400 nm) tends to be absorbed in the eye lens (<400 nm) and in the cornea (<300 nm), where it can produce injuries at relatively low powers due to photochemical damage. <br />
<br />
'''Visible light''' (400–700 nm) is mainly absorbed by the retina, where it can cause both photochemical and thermal damage at high intensities or prolonged exposure. Blue light (400–500 nm) is particularly hazardous as it can lead to photochemical damage to the retinal cells, even at lower power levels.<br />
<br />
'''Infrared light''' (>700 nm) mainly causes thermal damage to the retina at near-infrared wavelengths and to more frontal parts of the eye at longer wavelengths.<br />
<br />
The table below summarizes the various medical conditions caused by lasers at different wavelengths, not including injuries due to pulsed laser radiation.<br />
<br />
{| class="wikitable"<br />
! Wavelength range !! Effects<br />
|-<br />
|180–315 nm (UV-B, UV-C) || Photokeratitis (inflammation of the cornea, equivalent to sunburn)<br />
|-<br />
|315–400 nm (UV-A) || Photochemical cataract (clouding of the eye lens)<br />
|-<br />
|400–780 nm (visible) || Photochemical damage to the retina, retinal burn<br />
|-<br />
|780–1400 nm (near-IR) || Cataract, retinal burn<br />
|-<br />
|1.4–3.0 µm (IR) || Aqueous flare (protein in the aqueous humour), cataract, corneal burn<br />
|-<br />
|3.0 μm–1 mm || Corneal burn<br />
|}<br />
<br />
Note that the blink reflex is only triggered for light in the visible region, as the eye cannot detect UV or IR light. This makes these wavelength regions particularly dangerous, as a significant exposure may happen without the user being aware.<br />
Concerning laser-induced skin injuries, these depend on the power and type of laser, as listed below.<br />
<br />
{| class="wikitable"<br />
!Type !! Description<br />
|-<br />
|Thermal burns || Lasers operating in the visible and IR regions can cause thermal burns due to the absorption of laser energy by the skin, which is then converted to heat. This can result in mild burns (redness, swelling) or severe burns (blisters, tissue damage), especially when working with high-power lasers (e.g., Class 4 lasers).<br />
|-<br />
|Photochemical damage || UV lasers (<400 nm) can cause photochemical reactions in the skin, leading to erythema (similar to sunburn) or, over time, increasing the risk of skin cancer due to DNA damage. Long-term exposure to UV lasers can be particularly dangerous.<br />
|-<br />
|Mechanical damage || High-energy pulsed lasers can cause mechanical damage by creating rapid pressure changes in tissues. This can result in localized skin trauma or tissue fragmentation (bruising, tissue tearing, or open wounds)<br />
|}<br />
<br />
===Other laser parameters===<br />
From the viewpoint of laser safety, apart from wavelength lasers can be described based on additional key parameters. The table below lists the main factors that directly influence the potential hazards a laser presents and the safety measures that should be applied.<br />
<br />
{| class="wikitable"<br />
|'''CW lasers''' || Continuous Wave (CW) lasers emit a constant beam of light over time, meaning their power output is steady. The risk to eyes and skin depends on the total power output and the duration of exposure. Prolonged exposure to CW lasers, especially at high powers, increases the risk of thermal damage. <br />
For CW lasers, exposure limits are set based on the power and duration of the beam. Eye protection and beam control are crucial for high-power CW lasers.<br />
|-<br />
|'''Pulsed lasers''' || Pulsed lasers emit light in short bursts or pulses, with very high peak powers during each pulse, even if the average power over time is low. Pulsed lasers can deliver a large amount of energy in a very short period, making them particularly hazardous. Pulses are often used in applications like material ablation and medical procedures. <br />
For pulsed lasers, the peak power and pulse duration are critical. Even short exposure to a single pulse can cause severe damage to eyes or skin, depending on the laser's energy and repetition rate. Special care must be taken to limit exposure.<br />
|-<br />
|'''Energy''' || This parameter is typically measured in joules (J) and refers to the amount of energy delivered per pulse for pulsed lasers. The higher the energy, the greater the potential for damage, especially in pulsed lasers where a single pulse can cause significant harm. <br />
The energy per pulse is a critical factor in determining the level of eye protection needed. Pulsed lasers with high energy per pulse are particularly dangerous, as they can cause immediate damage to tissues, especially the retina.<br />
|-<br />
|'''Power''' || This parameter is usually measured in watts (W) and describes the rate at which energy is delivered. For CW lasers, power is the primary safety concern. Higher power means more energy is delivered over time, increasing the risk of burns and thermal injuries. <br />
Higher-power lasers, both CW and pulsed, require strict control measures, including the use of protective eyewear, proper beam enclosures, and controlled access areas to prevent accidental exposure. The power output must be factored into determining maximum permissible exposure (MPE) limits.<br />
|-<br />
|'''Beam size''' || Beam size refers to the diameter of the laser beam at the point of emission or at the target area. A smaller beam size concentrates the laser energy over a smaller surface area, potentially increasing the intensity of the beam and its risk of causing localized damage to tissues.<br />
A smaller, highly focused beam poses a greater hazard to localized areas of the skin or eyes. Appropriate shielding and precision in alignment are essential to prevent accidental exposure.<br />
|-<br />
|'''Beam divergence''' || Beam divergence is the degree to which a laser beam spreads as it propagates away from its source, usually measured in milliradians (mrad). Lasers with low divergence remain focused over long distances, maintaining their hazardous potential far from the source, whereas lasers with high divergence spread out more quickly, reducing their intensity over distance.<br />
Lasers with low divergence pose a greater risk to distant objects, making it critical to establish clear boundaries and use warning signs for long-range laser applications. Diverging beams may still be hazardous at close range, so personal protective equipment and beam barriers are essential regardless of the divergence rate.<br />
|-<br />
|'''Exposure duration''' || Exposure refers to the duration of time a person or object is subjected to the laser beam. Even low-power lasers can be harmful with prolonged exposure, particularly to the eyes. Shorter exposure times reduce the chance of injury, while longer exposure increases the risk, especially with CW lasers. <br />
Exposure duration is especially important in settings where the laser beam is not properly controlled. The risk of eye injury increases dramatically with longer exposure to even moderate-power lasers. Safety measures such as automatic shut-off systems, beam shutters, and the enforcement of exposure time limits are necessary.<br />
|-<br />
|'''Pulse duration''' || Pulse duration (for pulsed lasers) is the length of time each laser pulse lasts, typically measured in femtoseconds (fs), picoseconds (ps), or nanoseconds (ns). Shorter pulse durations can lead to higher peak intensities, which increase the risk of damage even if the total energy or average power is low. <br />
Ultrafast lasers (with very short pulse durations) can deliver extremely high-intensity pulses that may cause immediate damage. Extra caution, such as using safety interlocks and barriers, is required when working with such lasers.<br />
|-<br />
|'''Repetition rate''' || Repetition rate (for pulsed lasers) is the frequency at which pulses are emitted, measured in Hertz (Hz). High-repetition-rate pulsed lasers fire pulses rapidly, meaning that even if the energy per pulse is moderate, the cumulative exposure can be substantial. A higher repetition rate increases the likelihood of injury over time.<br />
A high repetition rate raises the risk of cumulative damage, especially to the eyes, as the frequency of pulses increases the likelihood of repeated exposure. Controlling exposure through beam shutters or limiting access during operation is crucial. The repetition rate is also important when determining appropriate protective eyewear, as it affects the total dose of laser radiation over a given period.<br />
|}<br />
<br />
==Laser safety procedures and principles==<br />
This section outlines the immediate steps to take in the event of an injury caused by laser exposure to the eyes, skin, or other body parts whether to yourself or to others. In the event of any laser injury, speed is critical. In particular, prompt medical attention is essential for laser-induced eye injuries. Early treatment can help prevent long-term damage. Ensure that you read these instructions thoroughly to prevent any time loss during an emergency. <br />
<br />
===Emergency procedures===<br />
In the event of any accident involving laser exposure:<br />
<br />
{| class="wikitable"<br />
| '''Stop operation''' || Immediately stop the laser system and turn off the laser source to prevent further exposure<br />
|-<br />
| '''Isolate the area''' || Ensure the affected area is safe by controlling the laser beam and preventing anyone else from entering the hazard zone.<br />
|-<br />
| '''Evaluate the situation''' || Quickly assess the injury, focusing on the type of laser (CW or pulsed), wavelength, power, and duration of exposure. This information will be useful for medical personnel.<br />
|}<br />
<br />
===Type of laser exposure===<br />
{| class="wikitable"<br />
| '''Eye exposure''' || Symptoms: Flashing lights, loss of vision, blind spots, difficulty focusing, pain in the eyes, or the feeling of something "in the eye".<br />
* Do not rub the eyes as this can worsen the injury.<br />
* Seek immediate medical attention: laser eye injuries can be serious, especially when the retina or cornea is affected.<br />
* Minimize further exposure: ensure that the person is kept in a dimly lit environment until medical help arrives to avoid strain on the injured eye.<br />
* Contact an ophthalmologist: even if the injury seems minor, all laser eye injuries should be evaluated by an eye specialist as soon as possible.<br />
|-<br />
| '''Skin exposure''' || Symptoms: Redness, swelling, burns, blistering, or pain on the affected skin area. Laser-induced burns can range from minor to severe, depending on the laser class and exposure.<br />
* Cool the burn: gently run cool (not cold) water over the affected area for 10 to 20 minutes.<br />
* Avoid applying ice or ointments: these can worsen the injury, especially if the burn is deep.<br />
* Cover the burn: Use a clean, sterile dressing to cover the burn to prevent infection. Avoid using adhesive bandages directly on the wound.<br />
* Seek medical attention: for severe burns or if large areas of skin are affected, professional medical evaluation and care are necessary.<br />
|-<br />
| '''Inhalation of fumes or debris''' <br/ >(from laser processing) ||Symptoms: Respiratory irritation, coughing, shortness of breath, dizziness, or nausea due to inhalation of harmful fumes from materials vaporized by the laser (e.g., plastics, metals).<br />
* Move to fresh air: ensure the affected person moves to a well-ventilated area away from the source of fumes.<br />
* Call for medical help: If the person continues to experience respiratory issues or dizziness, seek medical evaluation.<br />
* Prevent further exposure: identify the source of hazardous fumes and take steps to ensure proper ventilation before resuming work.<br />
|}<br />
<br />
Report the incident to the LSO, detailing the laser type, incident location, nature of the injury, and actions taken. Ensure proper documentation for legal and medical purposes.<br />
<br />
==Personal protection and control measures==<br />
Working with high-power lasers (Class 3B and Class 4) presents significant hazards, including severe eye and skin injuries, as well as the potential for indirect hazards such as fires. Therefore, it is critical to implement stringent personal protective equipment (PPE) and control measures to minimize the risks of accidental exposure.<br />
<br />
===Personal Protective Equipment (PPE)===<br />
{| class="wikitable"<br />
| '''Laser safety eyewear''' || <br />
* Eye protection is the most important PPE in a laser lab, as even brief exposure to a high-power laser beam can result in permanent eye damage.<br />
* Always wear laser safety eyewear whenever the lasers are turned on. There are no exceptions to this rule.<br />
* Safety goggles are available at the entrance to the lab. Select the model specifically rated to the laser wavelength that you will be using and place them before entering the lab<br />
* Ensure that all personnel wear appropriate laser eyewear whenever a high-power laser is in operation, and no exceptions should be made, even for brief entries into the lab.<br />
* Laser protective eyewear is not a substitute for other precautions. Adequate control measures should ensure the highest degree of protection possible.<br />
* Eyewear is marked to show the wavelength(s) for which it provides protection and the level of protection. The level of protection required for each laser is listed on the door safety sheets.<br />
|-<br />
| '''Protective clothing''' || <br />
* All lab users should wear lab coats to protect against potential thermal injuries.<br />
* Gloves are available at the entrance and should be used when working directly with laser equipment to prevent skin exposure.<br />
|}<br />
<br />
===Control measures===<br />
{| class="wikitable"<br />
| '''Basic safety measures''' || In a laser laboratory safety is fundamental. Excuses such as “being in a hurry”, “not having the proper components” or “just doing a quick test” are no justification for overlooking the basic rules below!<br />
* Ensure that all mechanical setups, mounts and optics defining the beam path are securely mounted and attached to an optical table<br />
* Laser beam paths must be as short as reasonably practicable, clear of surfaces producing hazardous reflections and confined to a single optical table<br />
* Remove or cover any personal reflective items (e.g. watches, rings) when using a laser<br />
* Do not place reflective objects near the beam path (e.g. cell phones, glasses, computer screens) <br />
|-<br />
| '''Beam enclosures, barriers and beam dumps''' || Physical barriers help contain the laser beam within a designated area and protect personnel from accidental exposure.<br />
* Enclose the laser beam path as much as possible using beam tubes or laser-safe panels.<br />
* Install laser beam dumps at the end of the beam path to safely capture and absorb the laser energy.<br />
* Beam dumps should be chosen according to handle the power and wavelength of the laser in use, ensuring they do not reflect or allow the beam to escape.<br />
|-<br />
| '''Warning signs and labels''' || Signage is available to inform personnel and visitors about the presence of laser hazards.<br />
* Pay attention to the warning signs at the lab, in particular those indicating the class of laser in use and the laser characteristics.<br />
* Be mindful of any changes to the laser configurations and setups which may involve the need for updates regarding laser hazards.<br />
|}<br />
<br />
=Daily operation and maintenance=<br />
This chapter lists the basic instructions for preparing, conducting and completing experiments at L2I.<br />
<br />
==Before an experiment==<br />
All proposed experiments, whether by internal or external users, must undergo a preliminary review by the CE and LH to assess the feasibility, safety, and availability of resources. The procedure for proposing an experiment starts with filling the Proposal Template (TBD)<br />
The experiment proposal must include: <br />
* objectives, required equipment, estimated length and anticipated results<br />
* list of participants, including their approval status; new users will have to undergo laser safety training to obtain approval<br />
* detailed risk assessment of potential hazards<br />
* laser sources to be used and laser safety plan (e.g., proper eyewear, beam enclosures, beam dumps)<br />
* main equipment list (optical components, instruments, detectors, etc). Verify their availability and proper functioning.<br />
* proposed experimental configuration, including the layout of the laser, optical components, and targets, must be reviewed and approved by the **Laser Safety Officer (LSO)** before commencing work.<br />
<br />
==During an experiment==<br />
Most of this Safety Manual already deals with the proper attitude towards safety in the course of an experiment. The rules below complement all the previous information.<br />
* ensure that only authorized personnel are allowed in the main laser hall.<br />
* whenever a laser is used, ensure that the correct status is shown on the laser safety display at the entrance.<br />
* double-check with anyone entering the lab that they are wearing the correct type of laser PPE.<br />
* allocate sufficient time for experimental setup, including preliminary checks, beam alignment, and safety verifications.<br />
* ensure enough time is available to dismantle the setup once the experiment is complete.<br />
<br />
==After the experiment==<br />
* evaluate if all safety measures worked as expected and identify any potential improvements for future experiments.<br />
* ensure all equipment is returned to its designated locations and that any damaged or faulty equipment is reported to the CE.<br />
* ensure proper disposal of all materials used during the experiment.<br />
* clean up the workstation and ensure no hazardous materials, equipment, or tools are left behind that could pose a risk to the next user.<br />
<br />
The maintenance operations are from the responsibility of the chief engineer. All the urgent maintenance interventions should be booked as soon as possible, stopping the investigation work, if necessary – safety measures are more important for users than scientific deadlines. <br />
<br />
==Equipment requiring additional training==<br />
There are several components at L2I that require previous training to be properly used, some of which have already been described (e.g. lasers sources, crane). If you are unsure about how to use any of the devices below, contact first the CE or anyone familiar with their use.<br />
* Air Treatment Unit<br />
* vacuum pumps and vacuum control system<br />
* vacuum chambers<br />
* lab crane (see Section)<br />
* heavy-duty lift (outside the lab room)<br />
* gas cylinders (see Section 4.2)<br />
* laser diode drivers <br />
* Pockels cell drivers and other high voltage source<br />
* data acquisition equipment <br />
<br />
==Maintenance==<br />
Regular maintenance, both scheduled and when needed, is the responsibility of the CE. Any malfunction or request for extraordinary maintenance must be communicated immediately to the CE.<br />
<br />
<br />
=Additional information=<br />
==Preventive measures==<br />
L2I is equipped with a variety of preventive measures to detect and prevent safety-related incidents. Make sure that you are thoroughly familiar with them, their location and operation. The table below details the location of each relevant item. See also Section 7.3 for a detailed floor plan.<br />
<br />
{| class="wikitable"<br />
! Item !! Description<br />
|-<br />
|Electrical panel 1 <br />Electrical panel 2 || Location: north wall <br />General electrical panels, including labelled circuit breakers.<br />
|-<br />
|Electrical panel 3 || Location: south wall<br />Electrical panel for the interaction area, including labelled circuit breakers.<br />
|-<br />
|Automatic smoke detector || Location: ceiling<br />
|-<br />
|Portable extinguishers || Location: north wall and next to the basin<br />
|-<br />
Interlock system || Location: before the main room<br />
|-<br />
|First aid kit || Location: north wall<br />A basic first aid kit is available for minor injuries such as cuts or abrasions.<br />
|-<br />
|Individual protection equipment || Location: before the main room<br />Cleanroom PPE includes lab coats, overshoes, hair nets and latex gloves. Other PPE equipment includes hard hats, heavy duty gloves and face masks<br />
|-<br />
|Laser goggles || Location: before the main room<br />
Specific laser safety goggles are available, covering all the wavelengths used in the laboratory. Make sure to select the right one.<br />
|-<br />
|Emergency lights and fluorescent tape || In the event of a power cut, the emergency lights will be automatically turned on, allowing users to leave the laboratory. An auxiliary fluorescent tape path is marked on the floor.<br />
|-<br />
|Emergency key || Location: to the right of the main door, inside the laboratory<br />In the event of a power failure, the main door electric shutter may not work properly. In this case, the emergency key can be used to open the door.<br />
|-<br />
Emergency door Location: East wall, three-door exit<br />In the event of an emergency requiring users to exit the laboratory, the emergency door should be used. Although normally closed, this door opens to the outside by rotating the knob.<br />
|}<br />
In case any of the items listed above isn’t working properly, you should notify the CE. <br />
<br />
7.2 Electric panels<br />
L2I is equipped with three electrical panels. The main one is Panel 3.<br />
<br />
Panel 1 Panel 2 Panel 3<br />
<br />
The tables below detail the layout of the electrical panels.</div>Ist23437 Warning: Cannot modify header information - headers already sent by (output started at /afs/ist.utl.pt/groups/mysolutions/web/wiki/includes/session/PHPSessionHandler.php:35) in /afs/ist.utl.pt/groups/mysolutions/web/wiki/includes/WebResponse.php on line 74