Laser Safety Retraining

1. Laser Safety Retraining Radiological and Environmental Management Updated 01/2014

2. Laser Safety at Purdue

3. Laser Safety Program Personnel Laser Safety at Purdue • Laser safety at Purdue University is managed by the University Laser Safety Officer (LSO) and Radiological and Environmental Management (REM) • The laser safety program is overseen by the Purdue Laser Safety Committee(LSC) • This committee is made up of representatives, mostly LPIs and safety personnel, from multiple departments • The Purdue program follows: • Occupational Safety and Health Administration (OSHA) is responsible for laser safety • OSHA adopts the American National Standards Institute (ANSI) guidelines, using the General Duty Clause • Laser regulations come from ANSI Z136.1 – American National Standard for Safe Use of Lasers

4. Laser Safety Program Laser Safety at Purdue • When using a Class 3B or Class 4 laser, potential hazards from the direct beam exist to the eye and skin. • Purdue Executive Memorandum D-2 mandates the use of Class 3B and Class 4 lasers to be compliant with the Purdue Laser Safety Program. • Each laser project must complete the necessary paperwork, meet the training requirements, and be evaluated by the Purdue LSO (Laser Safety Officer)

5. Laser Classes – 1, 1M, 2, 2M, and 3R Laser Safety at Purdue • Class 1, 1M, 2, 2M, and 3R: • low to lower-medium powered lasers that will not produce eye/skin injury under manufacturer-intended use, and if not intentionally focused on the eye • lasers with one of these classifications are exempt from the laser registration requirements of Purdue University • Note: Class 3R was formerly known as Class 3a • If ANY laser is modified (e.g. power, focusing, etc.), regardless of its initial classification, the LSO will need to perform an analysis to determine classification..

6. Laser Classes – 3B and 4 Laser Safety at Purdue • Class 3B (powers from 5 mW to 500 mW): • Can cause eye injury with direct exposure to beam • 3B lasers close to the maximum power of 500 mW may also cause eye injury by reflections of the beam • Normally not a fire hazard • Class 4 (powers greater than 500 mW): • Can cause eye injuries with the direct beam or with the reflected beam • Can cause injuries to the skin • Can be a fire hazard • May also be a source of laser generated air contaminants (LGACs) and hazardous plasma radiation.

7. Required Training Laser Safety at Purdue • All restricted and unrestricted users on laser projects must complete Purdue’s Online Laser Safety Training. • The LPI is not exempt, even if their use of the laser systems are infrequent • Initial Training requires completion of three steps: • Successful completion of the Initial Online Training • Attendance of the Classroom Training, unless you are a restricted user • Laser-specific training provided by LPI or by an experienced unrestricted user on the project

8. User Categories Laser Safety at Purdue • Restricted User: • Someone who works with a Class 3B or 4 laser only under direct physical supervision of their laser principal investigator or an authorized unrestricted user, or • Someone who does not operate the laser, but does work within the nominal hazard zone (as defined by the laser safety officer) of a Class 3B or 4 laser while the laser is in operation • Unrestricted User: • Has been approved by the LSO and the LPI to use the laser without supervision • Can supervise restricted users

9. LPI Responsibilities Laser Safety at Purdue Laser Principal Investigator (LPI) • Issues appropriate instruction and training materials on laser hazards of their specific laser • Ensures that operation of the laser meets all safety requirements, both for the lab members and anyone else who may enter the lab (custodial staff, visitors, etc.) • Ensures all individuals working have submitted a completed LU-2 form, including LPI • Ensures LU-1 (that must be submitted to LSO) has all authorized individuals listed. Subsequent users may be listed with all required information either as an LU-1 addendum, or by written documentation to LSO. • Notifies the LSO of any known or suspected injuries • If necessary, assists in obtaining appropriate medical attention for any employee involved in a laser accident • Will not permit operation of a new or modified Class 3B or Class 4 laser under his/her authority without LSO approval. • Shall submit all required paperwork for new laser or facilities • Shall ensure that SOPs are available for each laser

10. Employee Responsibilities Laser Safety at Purdue Employees working with lasers • Will not energize or work with or near a laser unless authorized to do so by the laser’s supervisor • Shall comply with Purdue University Laser Safety Guidelines, LSO and LPI safety rules and procedures • Will inform his/her LPI of any known or suspected accident involving a laser under their LPI’s jurisdiction. If the LPI is not available, the employee will notify the LSO

11. 8 Things Every Laser User at Purdue Should Know if Asked

12. Introduction 8 Things to Know The following slides highlight information that every laser user should know if asked. If you do not know the answer to one of these questions, and you would like some more information after you have gone through this retraining, feel free to contact someone from the laser safety group at REM.

13. Number One 8 Things to Know Who is the current laser safety officer? Zach Tribbett ztribbet@purdue.edu 765-494-1478 HAMP B173H

14. Number Two 8 Things to Know What types of safety measures are in place in your lab? Examples include: Training Standard operating procedures Barriers when required Accurate signage Proper Eyewear

15. Number Three 8 Things to Know Where can I get a copy of the laser regulations (ANSI Z136.1)? • You may purchase a copy of your own from ANSI or the Laser Institute of America for approximately $150 • You may make a request to view REM’s copy

16. Number Four 8 Things to Know What types of lasers does your lab have and what are they used for? What is the hazard class of each laser? If you don’t know this, then you should not be working with the laser! This information should be included in your unit-specific training. This information is also found on the laser signage and in the standard operating procedures. Laser safety measures (ie. eyewear, barriers, safe distances, etc.) are determined by hazard class and are unit specific.

17. Number Five 8 Things to Know Where is your laser inventory? All users should know what types of lasers and how many lasers are located in their lab. This information can be found with the LPI or by contacting REM. Please keep in mind though, that REM’s records are only accurate if proper registration is completed for each laser.

18. Number Six 8 Things to Know Do you have appropriate laser safety eyewear for your laser? Proper eyewear is critical to safety if no engineering controls are in place. Eyewear is specific to the laser you are using. A pair that works for one laser may not work for another. They need to be OD and wavelength appropriate. Proper eyewear for your laser should be addressed in: • Your unit-specific training • Standard operating procedures • Signage

19. Number Seven 8 Things to Know Where are the training records for your lab? Training records are required for all safety training, including laser safety. A binder should be kept in your lab that has records of the safety trainings for all lab members. For laser safety training, the best approach is to print your confirmation email that you receive after successful completion of the trainings. You may also contact REM to obtain verification that you have completed the required trainings.

20. Number Eight 8 Things to Know Are your laser warning signs accurate, ANSI compliant, and correctly posted? If the proper notifications have been made to the LSO, this will be taken care of. If you notice that they are not appropriate, contact your LPI or the LSO to get replacements. These signs are specific to the lab and to the lasers found in that lab. A general laser warning sign is not appropriate. The signs should be posted at the nominal hazard zone, which is determined by the LSO during the evaluation of the laser. The sign shown below is an example of compliant laser signage.

21. Laser Beam Hazards

22. When is a laser hazardous? Laser Beam Hazards • Any laser that is Class 3B or 4 has the potential to cause permanent eye damage, and in certain cases, can cause injuries to the skin • The hazard potential of a laser is based of the Maximum Permissible Exposure (MPE), which is specific to the unit you are using • In order to determine the level of hazard associated with a specific laser, the LSO will calculate the MPE and the irradiance or radiant energy of the laser beam. These two values are then compared in order to determine the nominal hazard zone, the optical density of the eyewear required, and the barriers that are required. This is why it is critical that all lasers are properly registered with REM and evaluated by the LSO.

23. Mechanism of Injury Laser Beam Hazards A laser can produce a beam injury to the eye through these 3 mechanisms: • Thermal • Potential effects: charring, edema, hemorrhage • Photochemical (blue light and UV) • Potential effects: production of toxins and biochemical changes which may cause inflammation, lesions and lens opacities • Photoacoustic (short intense pulses) • Potential effects: explosive forces due to expanding gases

24. Corneal Hazards Laser Beam Hazards TARGET: Cornea Far IR (IRC): 3000 nm – 1 mm Mid IR (IRB): 1400 nm – 3000 nm Mid UV (UVB): 280 nm – 315 nm Far UV (UVC): 100 nm – 280 nm EFFECT: Mid IR and Far IR: Thermal Mid UV and Far UV: Acute inflammation and conjunctivitis, fluorescence of lens, corneal and lenticular opacities (“clouding”) cataractogenesis (peaks at 300 nm)

25. Retinal Hazards Laser Beam Hazards TARGET: Retina Near IR (IRA) : 700 nm – 1400 nm Visible Light: 400 nm – 700 nm EFFECT: Thermal burns, hemorrhage, scotoma (“blind spot”), photoretinitis (“blue light damage”)

26. Lens Hazards Laser Beam Hazards TARGET: Lens Near UV (UVA): 315 nm – 400 nm EFFECT: Development of cataracts

27. Increased Sensitivity of the Eye Laser Beam Hazards • Lower MPE limits may be required when normal protective mechanisms such as eye movement and pupil constriction are hindered. Inform your LPI if you think that you have a condition that may impact your susceptibility to the laser beam. • For example, individuals who have had pupil dilation performed will not have the natural defenses of the constricting iris which helps limit that amount of radiation entering their eye. • Also, advanced age of an individual may reduce the ability of the iris to contract.

28. Skin Injuries - Thermal Laser Beam Hazards A laser can produce a beam injury to the skin through these 2 mechanisms: • Thermal (from direct beam or specular reflection) for Near UV, Visible, and IR wavelengths • Potential effects: mild reddening (erythema) to blistering • Severity is dependent upon exposure dose rate, exposure dose, and conduction of heat away from the site of absorption

29. Skin Injuries - Photochemical Laser Beam Hazards A laser can produce a beam injury to the skin through these 2 mechanisms: • Photochemical (from scatter of beam, specular or diffuse reflection) for Mid UV and Far UV wavelengths • Potential effects: erythema to blistering, possibly carcinogenic • Effects are dependent upon wavelength and exposure dose

30. Types of Reflections Specular (Mirror-Like) Reflected wavelength is blurred and weaker than the direct beam Occurs when the wavelength of the laser beam is smaller than the irregularities of the surface the beam hits Diffuse Laser Beam Hazards • Reflected wavelength is nearly the same shape and intensity as the direct beam • Occurs when the wavelength of the laser beam is greater than the irregularities of the surface the beam hits

31. Avoiding Injuries from Reflections Laser Beam Hazards • Avoid having objects that may produce a specular reflection in or near the laser beam path (e.g. jewelry, tools, computer screens, etc.), unless deliberately used as part of the laser system (e.g. mirrors) • Surfaces that appear dull and pitted to our eyes may be a specular surface to beams of larger wavelengths

32. Non-Beam Hazards

33. Different Categories Non-Beam Hazards • Include physical, chemical, and biological agents, as well as human use issues. • May occur when: • material is exposed to a laser beam • laser-related materials are released into the atmosphere • Individuals contact system components • Note: the beam does not have to be on for there to be a non-beam hazard • Written SOPs shall address non-beam hazards, as well as beam hazards.

34. Physical Agents Non-Beam Hazards • Electrical Hazards • Collateral and Plasma Radiation • Fire Hazards • Explosion Hazards • Mechanical Hazards Associated with Robotics • Noise If you need a review regarding the contributing factors and effects, please review the Initial Laser Training for Class 3B and Class 4 Lasers.

35. Chemical Agents Non-Beam Hazards • Laser Generated Air Contaminants (LGACs) • Compressed Gases • Laser Dyes and Solvents • Assist Gases If you need a review regarding the contributing factors and effects, please review the Initial Laser Training for Class 3B and Class 4 Lasers.

36. Chemical Agents – Control Measures Non-Beam Hazards • Engineering controls preferred • Exhaust Ventilation • avoid recirculation of LGACs. • use enclosing hoods, if possible. • Respiratory Protection • for brief exposures or interim control measure. • If used, must comply with 29 CFR 1910.134 (OSHA), and Purdue Respiratory Protection Plan. • Process Isolation • physical barriers, M-S manipulators, or remote control apparatus. • certain applications (e.g. biomedical applications) require disinfection/sterilization of equipment after use. • Sensors and Alarms • Shall be installed in hazardous gas cabinets and other locations as appropriate (including exhaust ventilation ducts) • Should be used for toxic and corrosive chemical agents (e.g. halogens), and be able to detect the hazardous gas in a mixture of emitted gases • Must be properly shielded to minimize susceptibility to electromagnetic interference (EMI)

37. Biological Agents Non-Beam Hazards • LGACs: may be generated when a high-powered lasers interacts with biological tissue. • Infectious Materials: may survive beam irradiation and become airborne. • Consult ANSI Z136.3, Appendix F.

38. Human Factors Non-Beam Hazards • Ergonomics (e.g. workstation layout, worker-machine interface, handling techniques, area illumination, visual distractions) • Limited Work Space: There must be sufficient room for personnel to turn around and maneuver freely, without trip/fall hazards (e.g. wires or cables on floor) • Work Patterns: Unusual or long hours may affect worker alertness

39. Protection from Hazards

40. Engineering Controls – 1/4 Protection from Laser Hazards • Protective Housing – Require interlocks and appropriate labels. • Service Access Panels – Shall only be removed by service personnel; interlocked or removal tool and warning label required. • Key Control – Master switch that can initiate and terminate system operation shall be operated by a key or coded access. The key (or code) shall only be accessible to authorized personnel. • Viewing Windows, Display Screens, and Collecting Optics – shall incorporate suitable means to maintain the exposure to below MPE. • Beam Paths – separate requirements for fully open, limited open, and enclosed.

41. Engineering Controls – 2/4 Protection from Laser Hazards • Remote Interlock Connector – Class 3B should and Class 4 shall have this control to eliminate accessible radiation to below the MPE • Beam Stop or Attenuator - Class 3B should and Class 4 shall have this permanently attached control to eliminate accessible radiation to below the MPE when laser output is not required. • Area Warning Signs and Activation Warnings - Class 3B and Class 4 areas shall be posted with the appropriate signage, both for beam and non-beam hazards. • Activation Warning Devices - Class 3B should and Class 4 shall use this control during activation or startup

42. Engineering Controls – 3/4 Protection from Laser Hazards • Indoor Laser Controlled Area • Analysis shall be performed by the LSO • Requirements for Class 4 more strict than Class 3B. • Emergency Conditions – For emergencies, there shall be a clearly marked “Emergency Stop” available for deactivating the laser or reducing output to below the MPE. • Entryway Controls – Class 4 laser areas shall have one of the following • Non-Defeatable: for deactivation of laser or reducing output to below MPE in the event of unexpected entry into laser controlled area. • Defeatable: only if clearly evident that there is no laser radiation hazard at the point of entry. • Procedural: only when safety latches or interlocks are not feasible or are inappropriate (e.g. Surgery).

43. Engineering Controls – 4/4 Protection from Laser Hazards • Outdoor control measures - Lasers are not to be used outdoors without evaluation and approval by LSO. • Temporary Laser Controlled Areas – in case of service or other conditions where housing, panels are removed and MPE is exceeded • Controlled Operation • Equipment Labels – in accordance with FLPPS or IEC 60825-1 • Housing, • Control Panel (if separated from housing by more than 2 meters), and • Long Distance Beam Conduit (at intervals of 3 meters)

44. Administrative & Procedural Controls – 1/2 Protection from Laser Hazards • Standard Operating Procedures (SOPs) – shall be written and maintained with the laser(s) for reference regarding operation and alignment, maintenance and service, emergency for personnel injury and fire, and all applicable non-beam hazards (including electrical safety). • Output Emission Limitations – LSO may require if excessive power or radiant energy is deemed excessive. • Education and Training – required, must cover topics required by ANSI, records must be maintained. • Authorized Personnel – LPI authorizes, training and registration are conditions of authorization.

45. Administrative & Procedural Controls – 2/2 Protection from Laser Hazards • Alignment Procedures • Procedures shall be written for each laser requiring beam alignment. These procedures must include methods for alignments as well as protective measures required. • Spectators – Shall not be permitted unless • LPI has approved, • Spectators are informed of the hazards by authorized users, and • Appropriate protective measures are taken. • Service Procedures • Only those with the education and safety training commensurate with the laser contained within protective housing. Typically, certified technicians from the manufacturer.

46. Protective Equipment - Eyewear Protection from Laser Hazards • Required within the NHZ for Class 3B and 4 lasers • Non-beam hazards may exist which require additional eye protection (ANSI Z87.1) • LSO shall determine the OD for eyewear based on laser specifications. • Shall be permanently labeled with the OD and its corresponding wavelength. These cannot be written on the eyewear with a marker or pen, or affixed to the eyewear on a label. The markings have to be etched into the eyewear so they cannot be removed. New eyewear should be purchased when these etching can no longer be read. • Shall be cleaned and inspected to ensure proper condition. Only use eyewear that is in proper working condition (e.g. no cracks, bleach marks, missing/broken straps, etc.)

47. Protective Equipment - Barriers Protection from Laser Hazards • Window Protection • windows within NHZ shall be provided with an appropriate filter, barrier, or screen with reduces laser radiation to below all applicable MPE • must be labeled (etched into the window) with OD and corresponding wavelength, exposure time, and conditions under which protection is afforded • Barriers and Curtains • material shall be selected to withstand direct and diffuse reflection of beam • must not support combustion or release toxic fumes upon laser exposure. • must be labeled with threshold limits and corresponding exposure time, and conditions under which protection is afforded. • Viewing ports • must be labeled with OD and corresponding spectral region which shall be provided by the manufacturer. • Collecting Optics Filters • must be labeled with OD and corresponding wavelength, threshold limit and corresponding exposure time, and conditions under which protection is afforded.

48. Protective Equipment – Skin Protection Protection from Laser Hazards • Skin Protection - mostly applicable to Class 4 UV lasers • LSO shall determine if skin protection is needed. • Should be flame-retardant when working with a Class 4 laser • Best achieved through engineering controls that prevent access to the beam or reflections

49. Disposal of a Laser Non-Beam Hazards • Disposal (i.e. donation, remove all means of activation and disposed, destruction) • Laser Waste Disposal: waste disposal shall conform with Purdue University disposal requirements (see REM’s Hazardous Material Management webpage)

50. Non-Compliance and Injuries