Laser Safety--Standard Operating Procedures

====1 INTRODUCTION

A key element of any laser safety program in a research environment is a standard operating procedure, commonly called an SOP. Different institutions may have their own names for this document: operational safety procedures, activity hazard document, work authorization document, and so on. Regardless, the basic sections are the same, even if the format varies. From a laser safety perceptive, the SOP needs to be considered as a contract between the laser users and the laser safety officer (LSO) or safety department. While the focus of this guide is laser safety, a truly complete SOP contains a description of all hazards associated with laser work (toxic chemicals, pressure, radiation, electricity, etc.) and their planned mitigation procedures.

The principal investigator (PI) or supervisor must prepare an SOP detailing the methods, responsible individuals, and materials used with the laser and have this approved by the LSO before beginning research. The typical SOP contains the following information:

1. The location, building, and room

2. A description of the work to be performed

3. A description of the laser including the class and the beam characteristics listed on the manufacturer's label

4. The intended use of the device and the type of research

5. An analysis of the potential hazards and the establishment of safety parameters

6. The use of the appropriate personal protective equipment PPE (especially eye protective equipment) suitable to limit laser beam exposure

7. A description of the emergency procedures and contingency plan necessary to deal with accidents and injuries In addition, the SOP may include:

1. The sign-off on the line management that authorizes the individual to conduct research within the boundaries stated in the SOP

2. A diagram of the work area

3. The time frame during which the document is valid (expiration date)

====2 SOP FLOW

====2.1 THE PI OR RESPONSIBLE INDIVIDUAL DEVELOPS THE DRAFT SOP

Emergency, safety & hazard (ES&H) personnel may assist in drafting the SOP, but the PI has the primary responsibility. An important thought process occurs when individuals must state in black and white what they are going to do and how they are going to do it. Over involvement by ES&H personnel in an attempt to "help" may do more harm than good by removing the PI from the safety thought process. Safety must remain integral to the R&D development process. R&D personnel must be safety conscious at all times.

====2.2 THE SOP MUST HAVE A COMPLETE AND ACCURATE WORK DESCRIPTION

A work description sets the boundaries within which the work will be conducted.

It’s an agreement between the experimenter and all reviewers and approvers regarding what work will be conducted. It can be amended and reviewed if the scope of work needs to change. It must be updated if and when the scope of work changes.

====2.3 HAZARDS MUST BE CLEARLY AND COMPLETELY IDENTIFIED

A checklist is helpful to ensure that nothing is overlooked. Every hazard should have some type of a stated control. All parties (PI, management, ES&H, facility personnel) should concur on the SOP.

====3 SAMPLE FORMAT

4. ====1 GENERAL INFORMATION

1. Title

2. Location of work

3. Date of preparation

4. Division

5. Activity supervisor (name of person with authority to designate experiment operators)

6. Principal investigator

4. ====2 DESCRIPTION OF ACTIVITY

Provide a brief summary of the work and a complete description of activities to be performed. Include details of unique equipment or materials and special application of standard equipment or materials. Include experimental parameters, such as quantities of chemicals used and stored, gas pressures, operating temperatures, voltages, current, and so on. Describe energy sources (electrical, pressure, gravitational, chemical, thermal, etc.). Describe the temporal aspects of the work (continuous or periodic, around the clock, etc.). Describe the need for and basis for any engineering notes appended to the SOP.

4. ====3 IDENTIFICATION OF HAZARDS

A comprehensive hazard identification and hazard analysis must be performed to identify the potential hazards associated with the activity. The relationship of the identified hazards and their potential effects on the experimenter, proximate personnel, the public, property, and the environment should be analyzed. The preferred hazard identification and analysis is specific and not generic (e.g.,"electrical shock" is insufficient; "contact with live 220V AC power from the bus bar if front panel is removed or if interlock is bypassed" is more appropriate).

General identification can work if, in addition, SOP specific hazards are called out.

4. ====4 MITIGATION OF HAZARDS

Describe in detail the controls necessary to mitigate the identified hazards. Controls may include, but are not limited to, engineering controls (interlocks, special ventilation systems, fire detection and suppression systems), personal protection and other safety equipment (gloves, face shields, aprons, eyewash/safety shower, etc.), and administrative controls (lockout/tagout and other special operating procedures, distance or time constraints, special training, etc.).

4. ====5 HAZARDOUS MATERIAL HANDLING

Describe all hazardous materials involved. Include quantities used, as well as storage, handling, segregation of incompatibles, and labeling requirements.

Describe the process for communicating information on material safety data sheets (MSDSs). Describe how the MSDSs are maintained.

4. ====6 HAZARDOUS WASTE

Identify hazardous waste generated by the activity and disposal criteria. Deter mine the waste generated and the control and authorizations necessary to deal with it. This may include special training and permit and storage protocols. An additional factor is to identify any waste stream permits that may be required.

4. ====7 EMERGENCY PROCEDURES

Provide procedures designed to respond to emergencies that may be associated with the activities described above. Issues to consider may include:

1. Potential to ignite or fuel a fire

2. Special fire extinguishers or unique fire prevention measures

3. Special first aid or medical response criteria unique to the identified hazards

4. Notification of the responding fire department regarding unique fire safety or medical-response issues associated with the work

5. Discussion of unique medical implications with responding medical teams

6. Special emergency shutdown procedures

7. Impact of a sudden power failure

8. Emergency escape plan

9. Supplemental emergency communications needs

10. Hazardous material spill or release response (control, containment, and training) procedures

11. Inventory of spill or release response supplies

12. Emergency equipment inspection protocol and schedules

4. ====8 MAINTENANCE

Consider inspection and maintenance procedures for materials, equipment, and components identified in Section 4. ====4 as critical parts or components that can lead to a catastrophic failure. An example would be testing room access interlocks and eye wash showers.

4. ====9 AUTHORIZED USERS AND TRAINING

Provide a list of the authorized users and a list of required training courses prerequisite to becoming an authorized user. Include a matrix that documents users, formal EH&S training course requirements, training completion dates, refresher training dates, on-the-job training, and so on. Include a user signature line (with date) for each user to sign, confirming their understanding of and conformance with the SOP.

====4 FOLLOW-UP TO THE SOP

An on-site prestart review should be conducted before final approval to begin work. The PI, management, and ES&H should be represented. The scope of work, hazards, and controls are again discussed to ensure that nothing has changed.

Controls for hazards should be verified such as:

1. Correct laser eyewear present

2. Beam tubes in place

3. Interlocks installed, functioning, and tested

4. Proper warning devices such as signs and warning lights in place The SOP should be reviewed periodically (annually at least) to ensure there have not been significant changes to:

1. The work description

2. Hazard levels

3. Implementation of hazard controls

4. Authorized personnel

Two key elements for a laser-based SOP are laser alignment procedures and laser controls. Following is a sample of laser alignment guidance, followed by a list of useful boilerplate laser control items that should be included in all laser based SOPs.

===4.1 PREPARATION FOR ALIGNMENT

1. To reduce accidental reflections, remove watches, rings, dangling badges, necklaces, and reflective jewelry before any alignment activities begin. Use of nonreflective tools should be considered.

2. Access to the room or area is limited to authorized personnel only.

3. Consider having at least one other person present to help with the alignment.

4. All equipment and materials needed are present prior to beginning the alignment.

5. All unnecessary equipment, tools, and combustible materials (if the risk of fire exists) have been removed to minimize the possibility of stray reflections and nonbeam accidents.

6. Persons conducting the alignment have been authorized by the responsible individual.

7. A notice sign is posted at entrances when temporary laser control areas are set up and when unusual conditions warrant additional hazard information being available to personnel wishing to enter the area.

===4.2 ALIGNMENT METHODS TO BE USED FOR THIS LASER

===4.2.1 Alignment Considerations

1. Whoever moves or places an optical component on an optical table (or in a beam path) is responsible for identifying and terminating each and every stray beam coming from that component (meaning reflections, diffuse or secular).

2. There must be no intentional intrabeam viewing with the eye.

3. Coaxial low-power lasers should be used when practical for alignment of the primary beam.

4. Reduce beam power with ND filters, beam splitters, or dumps or by reducing power at the power supply. Whenever practical, avoid the use of high-power settings during alignment.

5. Laser protective eyewear must be worn at all times during the alignment, within the parameters and notes specified in the accompanying laser table.

6. Beam blocks must be secured (and labeled if possible).

7. Have beam paths at a safe height, generally below level when standing or sitting.

8. The LSO has authorized eyewear with reduced optical density (OD) to allow the beam spot to be seen. Measures shall be taken and documented to ensure that no stray hazardous specular reflections are present before the lower-OD eyewear is worn. Maximum-OD eyewear, as listed in the laser table, is to be worn again once alignment is complete. The reduced-OD eyewear is labeled as alignment eyewear and is stored in a different location than the standard laser eyewear for this operation.

9. Skin protection should be worn on the face, hands, and arms when aligning at ultraviolet (UV) wavelengths.

10. The beam is enclosed as much as practical. The shutter is closed as much as practical during course adjustments. Optics and optics mounts are secured to the table as much as practical. Beam stops are secured to the table or optics mounts.

11. Areas where the beam leaves the horizontal plane must be labeled.

12. Any stray or unused beams are terminated.

13. Invisible beams are viewed with infrared (IR)/UV cards, business cards, card stock, craft paper, viewers, index cards, thermal fax paper, or Polaroid film or by a similar technique. Operators are aware that such materials may produce specular reflections or may smoke or burn.

14. Pulsed lasers are aligned by firing single pulses when practical.

15. Intrabeam viewing is not allowed unless specifically evaluated and approved by the LSO. Intrabeam viewing is to be avoided by using cameras or fluorescent devices.

====4.2.2 Alignment Conclusion

Normal laser hazard controls are to be restored when the alignment is completed.

Controls include replacing all enclosures, covers, beam blocks, and barriers and checking affected interlocks for proper operation.

====5 LASER CONTROL BOILERPLATES

The object of laser control boilerplates is not to repeat the requirements of a laser section, but rather to set forth a number of good practices to make sure all users read them as part of the SOP.

====5.1 GENERAL LASER CONTROLS

1. All laser operations must be conducted in accordance with the institution's EH&S laser safety section.

2. All operating personnel must have had a laser eye exam prior to working with class 3b or class 4 lasers.

==== All laser-operating personnel must have completed approved laser safety training prior to working with class 3b or class 4 lasers as well as an orientation to the laser experiment by the PI, including an explanation of the beam path, reflective surfaces, and hazards associated with the work.

4. The PI must be responsible for ensuring that all personnel, visitors, and students with access to the laser use area have a clear understanding of the controls associated with laser operation.

5. Laser operators must use appropriate OD laser protective eyewear.

6. This eyewear must be stored in such a manner as to protect its physical integrity. There must be sufficient laser protective eyewear on hand for users and expected visitors.

7. Laser areas must be kept as clean as possible. Reflective objects such as tools, optics, screws, and so on must be kept away from laser beams.

8. Appropriate laser warning signs, approved by the LSO, must be posted on all entrances to the laser use area.

9. In laser use areas that have room access interlocks, the interlocks must be tested quarterly. The results must be noted by the PI or designee on the interlock check sheet kept in the interlock check section of the SOP ES&H binder.

10. Laser beams should not be directed toward the entrances of any laser use area. In such cases, beam confinement or barriers must be in place to protect anyone entering the laser use area from direct exposure to laser radiation.

11. Whenever possible (within experimental considerations), appropriate enclosures, barriers, beam blocks, or beam tubes must be applied to contain laser radiation above the threshold that could cause eye or skin damage.

12. Any beam paths between tables or between laser tables and targets where an open walkway exists must have a control in place to block those in the room from crossing the pathway (e.g., hinged tubes, beam tubes, retractable tapes, or chains).

13. Whoever manipulates or moves optics is responsible for checking for stray reflections. When found, those reflections must be contained to the optical or experimental table(s), even if they are below an eye hazard level.

14. The LSO must be notified if any lasers are added or any experimental changes are made to an approved laser set-up that impact safety. At such times, the LSO must perform a hazard evaluation.

====6 SAMPLE LASER SOP1

====6.1 LASER SAFETY CONTACTS

Primary laser operator:____________ Phone:__________ Laser safety officer:_______ Phone:__________ Maintenance/repair:_______ Phone:__________ Medical emergencies:______ Phone:__________

====6.2 LASER DESCRIPTION

1. Location of laser or laser system (site, building, room)

2. Diagram of area layout with beam path, including locations of emergency shut-offs, fire extinguishers, protective equipment (eyewear), and barriers (attachment)

3. Description of each laser, including classification, lasing medium, and beam characteristics (divergence, aperture diameter, pulse length, repetition rate, and maximum output, as applicable)

4. Purpose and application of beams

====6.3 LASER SAFETY PROGRAM

Clearly outline each category below:

1. Responsibilities of the laser operators

2. Security or warning system activation or key control

3. Safety procedures

4. Laser training requirements

5. Personnel protective equipment requirements

====6.4 OPERATING PROCEDURES

1. Initial preparation of laboratory environment for normal operation (key position, outside status indicator on, interlock activated, warning sign posted, personnel protective equipment available, etc.)

2. Target area preparation

3. Special procedures (alignment procedures, safety tests, maintenance tests, etc.)

4. Operating procedures (power settings, Q-switch mode, pulse rate, etc.)

5. Shutdown procedures Laser: Date:

Department: Location:

====6.5 CONTROL MEASURES

Comments:

Laser/Laser System Controls Check if applicable Control Comments

[ ] Entryway (door) Interlocks or controls

[ ] Laser enclosure interlocks

[ ] Laser housing interlocks

[ ] Emergency stop/panic button

[ ] Master switch (operated by key or code)

[ ] Laser secured to base

[ ] Beam stops/beam attenuators

[ ] Protective barriers

[ ] Warning signs

[ ] Reference to equipment manual

[ ] Extra eyewear available Hazards and Controls Check if applicable Hazard Controls

[ ] Unenclosed beam/ Access to direct or scattered radiation

[ ] Laser at eye level of person sitting or standing

[ ] Ultraviolet radiation/blue light exposure

[ ] Reflective material in beam path

[ ] Hazardous materials/waste(dyes, solvents, other)

[ ] Fumes/vapors

[ ] Electrical

[ ] Capacitors

[ ] Compressed gases

[ ] Fire

[ ] Housekeeping

[ ] Trip hazard

Comments:

====6.6 PERSONNEL PROTECTION EQUIPMENT

A. Eyewear B. Other Protective Equipment Required within Nominal Hazard Zone Item Location Usage Condition

====6.7 OPERATOR REVIEW

I have read and understood this procedure and its contents and agree to follow this procedure each time I use the laser or laser system.

Name (print) Signature Date

====7 LASER AND LASER SYSTEM SOP GUIDELINES

I. Guidelines for SOPs Written SOPs must address normal operations as well as beam alignment for each laser or laser system. In addition, they should include nonbeam hazard management and servicing of the laser or laser system.

Keep SOPs brief to increase their probability of use.

It may be helpful to utilize the laser safety manual and the laser training form in developing your SOP.

The Office of Environmental Health & Safety will be happy to review and comment on your draft SOP. The LSO may be reached at ___ Laser Eyewear For this laser…. …Wear this eyewear Acquisition

#Type Wavelength(s) (nm) Wavelength(s) Attenuated (nm) Optical Density(OD) Remarks Example Nd:YAG 1064,532 1064,532 5+ UVEX

II. Beam alignment (concerns to be addressed in the SOP) A. Security: Secure the lab to avoid distractions by marking the door with an appropriate sign or marker such as "NOTICE: Laser Work In Progress. Do Not Enter. Eye Protection Required." B. Beam Characteristics: Is the beam visible or invisible? Is special equipment needed to view the beam? If the beam is pulsed, is it possible to fire one pulse at a time to limit exposure time and hazards? C. Beam Viewing: Intrabeam viewing is prohibited on Tulane campuses, and a remote viewing device should be used if intrabeam viewing is required for beam alignment. Only diffuse reflections may be viewed directly. Always use the lowest beam power possible that will still allow viewing of an image with proper protective eyewear.

D. Personal Protective Equipment (PPE): Use laser protective eye wear with a low enough OD to allow viewing of the diffuse reflection. Use appropriate body shields (gloves, lab coat, UV face shield) to protect against UV beam scatter.

E. Personnel: It’s ideal to have two people involved in the alignment process at all times. If this is not possible, at least let someone know where you will be and when you plan to have the alignment process completed. Regular check-ins are advised.

F. Replace Beam Controls: Ensure that all beam locks, enclosures, and beam barriers are replaced when the alignment is complete.

G. Remove Door Signs: Verify that the "NOTICE: Laser Work In Progress. Do Not Enter. Eye Protection Required." sign is removed from the room entrance and that the regular ANSI laser warning is still in place.

III. Normal operation of the laser (concerns to be addressed in the SOP) A. Security: Doors opening to areas where lasers are in use must be secure. A closed door does not constitute security. Doors must be rendered unopenable by using standard door locks or by activating door interlocks.

B. Personal Protective Equipment: Have the appropriate safety equipment on hand. Specify what is needed and its specific use.

C. Start-Up Procedures: Insert key, turn on water, turn on power supply, close shutter, activate laser, and so on as specific to your laboratory.

D. Experimental Procedure: Specific to your laboratory.

E. Emergency Procedure: Note the location of the emergency shut off mechanism, emergency procedure posting, fire extinguisher, safety shower, emergency eyewash station, and so on.

F. Shutdown Procedure: Specific to your laboratory.

G. Storage: Remove laser activation key and deactivate interlocks.

Store these devices in a secure location.

IV. --Nonbeam hazards to address-- (concerns to be addressed in the SOP) A. Electrical Hazards: Only properly trained personnel may work with high-voltage systems. It’s ideal to have two people involved in the alignment process at all times. If this is not possible, at least let someone know where you will be and when you plan to have the alignment process completed. Regular check-ins are advised.

Laboratory staff may be trained in CPR as a precaution.

B. Fire Protection: Attention should be given to preventing fires and explosions. Flammable solvents are frequently used as laser dyes and to clean optical parts. Fire extinguishers should be well marked and staff should be versed in their proper classification and use.

C. Compressed Gases: Staff should be trained in the safe management of cylinders and the associated hazards of the compressed gases being used.

D. Toxicity of Lasing Media