Laser Safety Training: Online Segment Radiological and Environmental Management Purdue University with information from ANSI Z136.1 - 2007 Welcome to Purdue University’s Initial Laser Safety Training. This training is required for all users of Class 3B and Class 4 Lasers and laser systems, and covers topics required by the ANSI Z136 series of laser safety standards, as well as Purdue’s own laser safety program requirements.

Modules 1 Fundamentals of laser operation 2 Bioeffects of laser radiation on the eye and skin 3 Significance of specular and diffuse reflections 4 Non-beam hazards of lasers 5 Laser and laser system classifications 6 Control measures 7 Laser Safety Project Information 8 Facility and personnel responsibilities 9 Medical surveillance practices 10 Required training 11 Consequences of Non-Compliance 12 Emergency Procedures

Module 1 Fundamentals of Laser Theory and Operation Laser Definition Laser Components Laser Characteristics In this module, we will discuss the fundamentals of laser theory and operation, which include the definition of a laser, what its components are, and it characteristics.

What is a laser? LASER: an acronym for Light Amplification by the Stimulated Emission of Radiation Laser System: a laser and its associated electrical, mechanical, and optical components. UV lamps, light boxes are NOT lasers The term “LASER” is an acronym for Light Amplification by the Stimulated Emission of Radiation A Laser System is a laser and its associated electrical, mechanical, and optical components, such as beam defractors and attenuators. Ultraviolet (or “UV”) lamps and light boxes are NOT lasers, as they operate under different physical conditions and emit incoherent electromagnetic radiation.

Laser Components Optical Cavity: resonator that provides the necessary geometry Resonator encapsulated by a fully-reflective mirror on one end and a partially-reflective mirror on the other.

Laser Components (2) Lasing Medium: causes amplification of a certain incident light at a particular wavelength. Solid-state Gas Dye Semi-conductor Atoms at “ground-state” awaiting stimulus from energy source.

Laser Components (3) Pumping System: imparts energy to the atoms or molecules of the laser medium. Optical pumping Collision pumping Chemical pumping Energy delivered to medium, causing excitation of atoms and the release of photons.

Q-Switch Provides laser pulses of an extremely short time duration. A Q-switch in the optical path is a method of providing laser pulses of an extremely short time duration. The Q-switch may use a rotating prism, a pockels cell (which is a voltage-controlled wave-plate) or a shutter device to create the pulse.

Laser Characteristics Monochromatic: either a single wavelength or a relatively small range of wavelengths. VS. One characteristic of a laser is that they are monochromatic. Either a single wavelength or a relatively small range of wavelengths is emitted.

Laser Characteristics Monochromatic: either a single wavelength or a relatively small range of wavelengths. Directional: “parallel light beam” - small divergence over distance, unless purposely diverged (e.g. diffusing lenses). VS. Laser are also directional, emitting a “parallel light beam”. there is generally a small divergence over a given distance, unless purposely diverged. The purposeful divergence typically occurs with diffusing lenses.

Laser Characteristics Monochromatic: either a single wavelength or a relatively small range of wavelengths. Directional: “parallel light beam” - small divergence over distance, unless purposely diverged (e.g. diffusing lenses). Coherent: a “fixed phase” relationship exists within the wavelength – in step. VS. A final major characteristic of a laser is their coherence. The emitted wavelengths tend to march in step, with their crests occurring simultaneously.

Module 2 Bioeffects of Laser Radiation on the Eye and Skin Criteria for Eye and Skin Exposure Eye Tissues Mechanisms of Eye Injury Eye Hazard vs. Wavelength Special Considerations for Ocular Exposure Mechanisms of Dermal Injury In this module, we will discuss the Bioeffects of Laser Radiation on the Eye and Skin.

Criteria for Exposures of Eye and Skin Maximum Permissible Exposure (MPE) limits are below known hazardous levels. Exposures at the MPE limit may be uncomfortable. MPEs are normalized relative to the limiting aperture area – we assume the limiting aperture area is 7mm for the pupil size of a dark-adapted eye in most cases. Irradiance is affected by the Radiant Exposure and the Exposure Duration Maximum Permissible Exposure (MPE) limits are set below known hazardous levels in order provide a margin of safety, although exposures at the MPE limit may be uncomfortable. Calculations for the MPEs are based on the worst-case plausible scenario, which is having the pupil dilated at the largest normalized relative to the limiting aperture area – we assume the limiting aperture area is 7mm for the pupil size of a dark-adapted eye in most cases. Irradiance is affected by the Radiant Exposure and the Exposure Duration ANSI Z136.1-2007 Section 8: Criteria for Exposures of Eye and Skin

Eye Tissues Macula/Fovea Iris Optic Nerve Cornea Pupil Retina Lens Vitreous Body Retina

Eye Tissues Iris Optic Nerve Cornea Macula: devoid of blood vessels; area of eye most responsible for color vision. Fovea: center of macula; area of eye of clearest vision/focusing. Pupil Lens Vitreous Body Retina

Eye Tissues Macula/Fovea Iris Optic Nerve: transmits electrical impulses from the retina to the brain; fibers enter eye at the Optic Disk. Cornea Pupil Lens Vitreous Body Retina

Eye Tissues Macula/Fovea Iris Optic Nerve Retina: innermost coat of outside of eye, responsible for vision. Cornea Pupil Lens Vitreous Body

Eye Tissues Macula/Fovea Iris Vitreous Body: transparent, colorless, gelatinous material which fills the eyeball chamber. Optic Nerve Cornea Pupil Lens Retina

Eye Tissues Macula/Fovea Iris Optic Nerve Lens: focuses light onto the retina. Cornea Pupil Vitreous Body Retina

Eye Tissues Macula/Fovea Iris Pupil: opening in the center of the iris; pupil size determines amount of light entering eye. Optic Nerve Cornea Lens Vitreous Body Retina

Eye Tissues Macula/Fovea Iris: pigmented muscle that dilates and constricts, depending on ambient light. Optic Nerve Cornea Pupil Lens Vitreous Body Retina

Eye Tissues Macula/Fovea Iris Cornea: transparent, layered window of eye; provides 2/3 of eye’s focusing power. Optic Nerve Pupil Lens Vitreous Body Retina

Mechanisms of Eye Injury 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 The 3 primary mechanisms for eye injury are thermal, photochemical, and photoacoustic. Thermal exposure can produce charring, edema, hemorrhage. Photochemical exposure can cause the production of toxins and biochemical changes which may cause inflammation, lesions and clouding of the lens. Photoacoustic exposure can cause explosive forces to occur within the eye from the quick expansion and contraction of gases. ANSI Z136.1-2007 Section 8: Criteria for Exposures of Eye and Skin

Eye Hazard vs. Wavelength 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) Here you see the wavelengths that have potential to cause damage to the cornea, and the associated possible effects. ANSI Z136.1-2007 Section 8: Criteria for Exposures of Eye and Skin

Eye Hazard vs. Wavelength 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”) Here you see the wavelengths that have potential to cause damage to the retina, and the associated possible effects. ANSI Z136.1-2007 Section 8: Criteria for Exposures of Eye and Skin

Eye Hazard vs. Wavelength TARGET: Lens Near UV (UVA): 315 nm – 400 nm EFFECT: Development of cataracts Here you see the wavelengths that have potential to cause damage to the lens, and the associated possible effects. ANSI Z136.1-2007 Section 8: Criteria for Exposures of Eye and Skin

Special Considerations for Ocular Exposures 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 could limit that amount of radiation entering their eye. Also, advanced age of an individual may reduce the ability of the iris to contract. Lower MPE limits may be required when normal protective mechanisms such as when normal eye movement and pupil constriction are hindered. Inform your Laser Principal Investigator if you think that you have a condition that may impact your susceptibility to the laser beam. For example, individuals who have had a recent pupil dilation performed will not have the natural defenses of the constricting iris, allowing a greater amount of light in their eye. Also, advanced age of an individual may reduce the ability of the iris to contract. ANSI Z136.1-2007 Section 8: Criteria for Exposures of Eye and Skin

Mechanisms of Dermal Injury 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 Dermal, or skin, injury can occur from thermal exposure of near ultra-violet, visible, and infrared wavelengths. Exposure effects could range from mild reddening (or erythema), to blistering. The severity of the effect is dependent upon exposure dose rate, total accumulated exposure dose, and the conduction of heat away from the site of absorption.

Mechanisms of Dermal Injury 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 Dermal injury can also occur from photochemical exposure of mid and far ultra-violet wavelengths. Exposure effects could range from mild reddening (or erythema), to blistering. The severity of the effect is dependent upon exposure dose rate, total accumulated exposure dose, and the conduction of heat away from the site of absorption.

Module 3 Significance of Specular and Diffuse Reflections Specular Reflection Diffuse Reflection Specular vs. Diffuse Reflection Important Notes In this module, we will discuss the significance of specular and diffuse reflections.

Specular Reflection Mirror-like Reflection Reflected wavelength is near same shape and intensity as direct beam Obeys the Law of Reflection: Angle of Reflection = Angle of Incidence Occurs when wavelength of laser beam is greater than the irregularities of the surface the beam hits Specular, or “mirror-like” reflections occur when the wavelength of the laser beam is greater than the irregularities of the surface the beam hits. The reflected wavelength is approximately the same shape and intensity as the direct beam.

Diffuse Reflection Reflected wavelength is blurred and weaker than direct beam Obeys Lambert’s Law or the Cosine Law of Reflection Occurs when wavelength of laser beam is smaller than the irregularities of the surface the beam hits Diffuse reflections occur when the wavelength of the laser beam is smaller than the irregularities of the surface the beam hits. The reflected wavelength is blurred and less intense than the direct beam.

Specular vs. Diffuse Reflection Here is a diagram depicting the differences of specular and diffuse reflection. For the diffuse reflection, you can see that the photons are deflected at different angles, and some deflect upon the surface multiple times, forcing energy loss with each interaction.

Important Notes Avoid having objects that may produce a specular reflection in or near laser beam (e.g. jewelry, tools, etc.), unless deliberately used as part of laser system (e.g. mirrors) Surfaces that appear dull and pitted to our eyes may be a specular surface to beams of larger wavelengths When an open-beam laser is in operation, avoid having objects that may produce a specular reflection in or near laser beam (such as jewelry, tools, etc.), unless deliberately used as part of laser system (e.g. mirrors) and under proper alignment. Please remember that it is possible for surfaces that appear dull and pitted to our eyes may be a perfect mirror to beams of larger wavelengths.

Module 4 Non-Beam Hazards of Lasers General Information Physical Agents Chemical Agents Biological Agents Human Use In this module, we will discuss the non-beam hazards associated with lasers.

ANSI Z136.1-2007 Section 7: Non-Beam Hazards General Information 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. Written SOPs shall address non-beam hazards, as well as beam hazards. Non-beam hazards include physical, chemical, and biological agents, as well as human use issues. Non-beam hazards are taken quite seriously, as there have been deaths caused by these hazards. These hazards may occur when the material is exposed to a laser beam, the laser-related materials are released into the atmosphere, or when individuals contact system components. Written Standard Operating Procedures must be available and must address beam and applicable non-beam hazards. ANSI Z136.1-2007 Section 7: Non-Beam Hazards

ANSI Z136.1-2007 Section 7: Non-Beam Hazards Physical Agents Electrical Hazards Potential Hazards Shock: risk from contact with energized electrical conductors, power supplies, and other devices operating at potentials or 50 volts and above. (note: 600 volts and higher are considered to be High Voltage) Resistive Heating: routinely check equipment for decay. Electric Spark Ignition of Flammable Materials: malfunction can lead to fire; sparks may be ignition source. Potential effects: “tingle”, startle, serious injury, death. Electrical Hazard Control Measures: comply with OSHA, NFPA 70, and state and local regulations. Must have: Fire extinguishers designed for electrical fires. Panic Button or Emergency Shutdown Switch. The electrical non-beam hazard may cause shock, resistive heating, and electrical spark ignition of flammable materials. Potential biological effects range from tingling to serious injury or death. Control measures must comply with OSHA laws, NFPA 70 (also known as the National Electric Code), and state and local regulations. Work environments with potential electrical hazards must have fire extinguishers that are designed for electrical fires and a panic button or emergency shutdown switch, at a minimum. ANSI Z136.1-2007 Section 7: Non-Beam Hazards

ANSI Z136.1-2007 Section 7: Non-Beam Hazards Physical Agents (2) Collateral and Plasma Radiation Ionizing Radiation: x-rays from electronic components of laser system (e.g. voltages exceeding 15 kV) and laser-metal induced plasmas. Non-Ionizing Radiation: UV and Visible: suitably shielded so as not to exceed limits specified by the ACGIH TLVs. Electromagnetic Fields (EMF): MPEs set by IEEE C95 Plasma: UV and blue light The collateral and plasma radiation non-beam hazards may be produced by either ionizing or non-ionizing radiation. If there is a possibility that ionizing radiation is being emitted, REM will need to assess the exposure and make a determination as to what further measures will be required. ANSI Z136.1-2007 Section 7: Non-Beam Hazards

ANSI Z136.1-2007 Section 7: Non-Beam Hazards Physical Agents (3) Fire Hazards Use flame retardant materials wherever possible. Possible affected material: beam enclosures, barriers, unprotected wire insulation, and plastic tubing. Obtain appropriate fire protection information from manufacturer. Explosion Hazards Possible causes: component (high-pressure arc lamps, filament lamps, and capacitor banks) disintegration, laser target and elements of the optical train may shatter, chemical laser reactants or other laser gases, ignition of dust collected in ventilation systems serving laser processes. Required preventative measures: proper and timely maintenance of system, protective housing enclosure surrounding internal components, enclosure (or equivalent protection) of laser target and susceptible elements of optical train. The potential non-beam hazards of fire can be minimized by using flame retardant materials wherever possible. For instance, beam enclosures and barriers would need to be properly rated against ignition. Explosions could occur due to various factors, as listed here. Appropriate preventative measures can be taken to minimize this threat. ANSI Z136.1-2007 Section 7: Non-Beam Hazards

ANSI Z136.1-2007 Section 7: Non-Beam Hazards Physical Agents (4) Mechanical Hazards Associated with Robotics Potential hazards: damage to protective housing and beam delivery system, misalignment of beam, pinning/pinching of personnel. Protective measures: may include surface interlock mats, interlocked light curtains, non-rigid walls and barriers. Consult REM for further information. Noise: Certain lasers (e.g. pulsed excimers), and/or work environment may require noise control. Mechanical hazards from robotics present a set of unique hazards. In addition to potential direct biological effects, such as pinning or pinching, a robotic malfunction or misdirection could cause damage to the laser housing or beam delivery system and misalignment of the beam. Noise hazards are also possible, especially with rapidly-pulsed excimer lasers. If the noise hazard is sufficient, noise control may be required. ANSI Z136.1-2007 Section 7: Non-Beam Hazards

ANSI Z136.1-2007 Section 7: Non-Beam Hazards Chemical Agents Laser Generated Air Contaminants (LGACs) Primary Factors: target material, cover gas, and the beam irradiance. Lower limit of occurrence appears at an irradiance level of approximately 107 W/cm2. Possible carcinogenic toxic, and noxious airborne contaminants (list in Appendix F, ANSI Z136.1 – 2007). LSO must ensure industrial hygiene characterizations of exposure to LGACs are conducted properly and refer to Material Safety Data Sheets (MSDSs) supplied by the manufacturer. If necessary, LSO may require additional control methods. Chemical non-beam hazards include Laser Generated Air Contaminants (or LGACs). The primary factors that determine the production of LGACs are the target material, the cover gas, and the beam irradiance. If a laser has an irradiance level of approximately 107 W/cm2, this potential should be assessed by the Laser Safety Officer and REM’s Industrial Hygiene group. The presence of LGACs could introduce possible carcinogenic, toxic, and noxious airborne contaminants. If necessary, the Laser Safety Officer may require additional control methods. ANSI Z136.1-2007 Section 7: Non-Beam Hazards

ANSI Z136.1-2007 Section 7: Non-Beam Hazards Chemical Agents (2) Compressed Gases E.g.: chlorine, fluorine, hydrogen chloride, hydrogen fluoride. All compressed gases with a Hazardous Material Information System (HMIS) or NFPA Diamond with a health, flammability, or reactivity rating of 3 or 4 shall be properly contained (i.e in an approved and appropriately exhausted gas cabinet that is alarmed with sensors to indicate potential leakage conditions). SOPs shall be developed for safely handling compressed gases. Sample of associated safety problems: Free-standing cylinder not isolated from personnel. Failure to protect open cylinders (i.e. regulator disconnected) from atmosphere and contaminants. No remote shutoff valve or provisions for purging gas before disconnect or reconnect. Labeled hazardous gas cylinders not maintained in appropriate exhausted enclosures. Gases of different hazards (toxic, corrosive, flammable, oxidizer, inert, high pressure, and cryogenic) not stored separately in accordance with OSHA and Compressed Gas Association requirements. Compressed gases are another chemical non-beam hazard. Compressed gas cylinders must be labeled with the HMIS label or NFPA Diamond. If the potential release hazard is sufficient, more stringent containment control measures may be required. Anyone handling the compressed gases should be familiar with the Mate ANSI Z136.1-2007 Section 7: Non-Beam Hazards

ANSI Z136.1-2007 Section 7: Non-Beam Hazards Chemical Agents (3) Laser Dyes and Solvents Fluorescent compounds which, when in solution with certain solvents, form a lasing medium for dye lasers. Some are highly toxic or carcinogenic. Dye handling must employ special care (see Purdue University Chemical Hygiene Plan) Dye lasers containing 100 ml or greater of flammable liquids shall be in conformance with NFPA 30 and 45, and the NEC Article 500. All dyes shall be prepared in a laboratory fume hood. Dye pumps and reservoirs should be placed in secondary containment vessels to minimize leakage and spills in conformance with NFPA 115. Assist Gases May be used to produce an inert atmosphere, remove material from beam-interaction site, and minimize deposition on components. May appear in some types of LGACs and spectral distribution of plasma radiation. ANSI Z136.1-2007 Section 7: Non-Beam Hazards

ANSI Z136.1-2007 Section 7: Non-Beam Hazards Chemical Agents (4) Control Measures: Engineering controls preferred Exhaust Ventilation avoid recirculation of LGACs. use enclosing hoods, if possible. designed in accordance with ACGIH and ANSI Z9.2. Respiratory Protection for brief exposures or interim control measure. If used, must comply with 29 CFR 1910.134 (OSHA). Process Isolation physical barriers, master-slave 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). ANSI Z136.1-2007 Section 7: Non-Beam Hazards

ANSI Z136.1-2007 Section 7: Non-Beam Hazards Biological Agents 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. LGACs may be generated when high-powered lasers interact with biological tissues. Biological agents that are exposed to lasers may be “liberated” by the beam and become airborne. LGACs: may be generated when a high power laser interacts with biological tissue. Infectious Materials: may survive beam irradiation and become airborne. Consult ANSI Z136.3, Appendix F. ANSI Z136.1-2007 Section 7: Non-Beam Hazards

ANSI Z136.1-2007 Section 7: Non-Beam Hazards Human Factors 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 an maneuver freely, without trip/fall hazards (e.g. wires or cables on floor). Work Patterns Unusual or long hours may affect worker alertness. ANSI Z136.1-2007 Section 7: Non-Beam Hazards

ANSI Z136.1-2007 Section 7: Non-Beam Hazards Human Factors (2) Disposal Laser Disposal: donation, remove all means or activation and disposed, destruction Laser Waste Disposal: waste disposal shall conform with Purdue University disposal requirements (see REM’s Hazardous Material Management webpage) Chillers May be employed to reduce heat load produced by lasers. Chiller types: conductivity-cooled, air-cooled, or cooled with a closed loop chiller. If using chilled water, filter the incoming water to ensure that minerals and particulate matter are removed to minimize damage to equipment. ANSI Z136.1-2007 Section 7: Non-Beam Hazards

Laser and Laser System Classifications Module 5 Laser and Laser System Classifications In this module, we will discuss

Laser Classifications Class 1: exempt from control measures or other surveillance, considered incapable of producing damaging radiation levels during operation. Former Class IIa lasers are considered to be in this category. Class 1M: exempt from any control measures other than to prevent potentially hazardous optically aided viewing, considered incapable of producing hazardous exposure conditions during normal operation unless the beam is viewed with an optical instrument. ANSI Z136.1-2007 Section 1: General

Laser Classifications (2) Both Class 2 and Class 2M laser emit only in the visible spectrum (400 – 700 nm wavelengths). In the visible spectrum, the human aversion response (a reflex action of blinking and looking away from a strong optical stimulus) occurs when the eye becomes exposed; the response time occurs within 0.25 seconds. Class 2 lasers are considered harmless for accidental viewing based on the power level and protection of the human aversion response. Class 2M lasers are considered potentially hazardous if viewed with certain optical aids. For instance, a focusing lens may produce a magnified intensity to which the eye could be exposed. The Laser Safety Officer should evaluate a Class 2M laser or laser system to determine what hazard controls may be necessary for the safe use of the laser. ANSI Z136.1-2007 Section 1: General

Laser Classifications (3) Class 3 (medium power): may be hazardous for direct or specular reflections (normally not a diffuse reflection or fire hazard). 2 subclasses. Class 3R: potentially hazardous under some direct and specular reflection viewing conditions (if eye is focused and stable, highly improbable). Not a fire or diffuse reflection hazard. Class 3B: viewing hazard under direct or specular reflection conditions, normally not a diffuse reflection or fire hazard ANSI Z136.1-2007 Section 1: General

Laser Classifications (4) Class 4 (high power): Hazard to eye or skin from the direct beam, and May be a diffuse reflection or fire hazard May also be a source of laser generated air contaminants (LGACs) and hazardous plasma radiation. For lasers not classified by manufacturer, or where class level may change because of alteration of engineering control measures, the Laser Safety Officer (LSO) may classify Laser classifications are in Arabic Numerals; Roman Numerals are no longer accepted. ANSI Z136.1-2007 Section 1: General

Module 6 Control Measures General Rules Accident Trends Operation, Maintenance, and Service Unattended Use Laser Modification Engineering Controls Administrative & Procedural Controls Special Considerations Protective Equipment Area Warning Signs & Equipment Labels In this module, we will discuss

ANSI Z136.1-2007 Section 4: Control Measures General Rules Use minimum laser radiation required for the application. Maintain beam height at a level other that the position of the user’s eye standing or sitting. Prefer engineering controls, however must have administrative and procedural controls. ANSI Z136.1-2007 Section 4: Control Measures

ANSI Z136.1-2007 Section 4: Control Measures Accident Trends Reported incidents related to lasers are most often associated with: Unanticipated eye exposure during alignment Misaligned optics and upwardly directed beams Available eye protection not used Equipment malfunction Improper methods of handling high voltage Intentional exposure of unprotected personnel Operators unfamiliar with laser equipment Lack of protection for non-beam hazards ANSI Z136.1-2007 Section 4: Control Measures

ANSI Z136.1-2007 Section 4: Control Measures Accident Trends (2) Reported incidents related to lasers are most often associated with (cont’d): Improper restoration of equipment following service Eyewear worn not appropriate for laser in use Unanticipated eye/skin exposure during laser usage Inhalation of laser generated air contaminants and/or viewing laser generated plasmas Fires resulting from the ignition of materials Eye or skin injury of photochemical origin Failure to follow SOPs ANSI Z136.1-2007 Section 4: Control Measures

Operation, Maintenance, and Service Lasers are classified under conditions of intended use. Maintenance and Service functions should be delineated in the service manuals of the laser. Consult with manufacturer for special use conditions/service of laser. Consult REM Laser Section for guidance on service procedures. ANSI Z136.1-2007 Section 4: Control Measures

ANSI Z136.1-2007 Section 4: Control Measures Unattended Use Operate lasers under direct supervision or control of an authorized user – operator shall maintain visual surveillance of conditions for safe use and terminate laser operation in the event of malfunction or other unsafe condition. Unattended operation may ONLY be allowed under LSO-approved control measures are in place; control measures MUST provide adequate protection so that unprotected spectators shall not receive eye or skin exposures that exceed the MPE limits. Service Personnel Emergency Personnel Administrative/Other Personnel Students/General Public ANSI Z136.1-2007 Section 4: Control Measures

ANSI Z136.1-2007 Section 4: Control Measures Laser Modification LSO may reclassify a modified laser. May necessitate recertification, reclassification, and compliance reporting under Federal Laser Product Performance Standard (FLPPS). ANSI Z136.1-2007 Section 4: Control Measures

ANSI Z136.1-2007 Section 4: Control Measures Engineering Controls 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. ANSI Z136.1-2007 Section 4: Control Measures

Engineering Controls (2) 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. Warning 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. ANSI Z136.1-2007 Section 4: Control Measures

Engineering Controls (3) 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). ANSI Z136.1-2007 Section 4: Control Measures

Engineering Controls (4) 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) ANSI Z136.1-2007 Section 4: Control Measures

Administrative and Procedural Controls 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. ANSI Z136.1-2007 Section 4: Control Measures

Administrative and Procedural Controls (2) Alignment Procedures 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 Personnel – Only those with the education and safety training commensurate with the laser contained within protective housing. Typically, certified technicians from the manufacturer. ANSI Z136.1-2007 Section 4: Control Measures

Special Considerations General Public – Class 3B and 4 require a laser light show variance issued by the Center for Devices and Radiological Health (CDRH), other requirements. Optical Fiber Transmission Systems – considered enclosed within cable, if disconnecting where MEP is exceeded, NHZ requirements implemented. Robotic Installations – working envelope included in NHZ. ANSI Z136.1-2007 Section 4: Control Measures

ANSI Z136.1-2007 Section 4: Control Measures Protective Equipment General – enclosure of beam is the preferred method of control. Eyewear – Required within 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 labeled with the OD and its corresponding wavelength. Shall be cleaned and inspected to ensure proper condition. Only use eyewear that is in proper working condition. ANSI Z136.1-2007 Section 4: Control Measures

Protective Equipment (2) Window Protection – within NHZ shall be provided with an appropriate filter, barrier, or screen with reduces laser radiation to below all applicable MPE. 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. Labeling of Protective Equipment – Shall be permanently labeled with: Eyewear – OD and corresponding wavelength. Protective Windows – OD and corresponding wavelength, exposure time, and conditions under which protection is afforded. Collecting Optics Filters – OD and corresponding wavelength, threshold limit (TL) and corresponding exposure time, and conditions under which protection is afforded. Barriers (unless integral part of laser system) – TL and corresponding exposure time, and conditions under which protection is afforded. Viewports and Films (unless integral part of laser system) – OD and corresponding spectral region which shall be provided by the manufacturer. ANSI Z136.1-2007 Section 4: Control Measures

Protective Equipment (3) Skin Protection - mostly applicable to Class 4 UV lasers LSO shall determine if skin protection is needed. best achieved through engineering controls Other Protective Equipment – respirators, local exhaust ventilation, fire extinguishers, and hearing protection may be required. ANSI Z136.1-2007 Section 4: Control Measures

Area Warning Signs and Equipment Labels Design – In accordance with ANSI Z535. Symbols – 2 accepted symbols: Laser Symbol Design: ANSI Z535: sunburst pattern IEC 60825-1: equilateral triangle with sunburst pattern Safety Alert Symbol: equilateral triangle surrounding an exclamation mark – must conform with ANSI Z535.3. Signal-Words Danger: Class 3R, 3B, and 4; OD and corresponding wavelength must be on sign. Caution: Class 2 and 2M. Notice: Temporary laser controlled areas (e.g. service). ANSI Z136.1-2007 Section 4: Control Measures

Area Warning Sign Example

Area Warning Signs and Equipment Labels (2) Pertinent Sign Information – requirements: Appropriate signal word. Precautionary instructions or protective action. Laser type or emitted wavelength, pulse duration, and maximum output. Laser classification. Conspicuously displayed in best locations to warn onlookers. Pertinent Equipment Label Information – Different requirements for different classes, conspicuously displayed. Existing Signs – Signs and labels prepared in accordance with previous revisions are acceptable. ANSI Z136.1-2007 Section 4: Control Measures

Module 7 Laser Safety Project Information Forms Personnel Responsibilities & Requirements In this module, we will discuss

Project Approval Process Forms must be completed and approved by LSO, LSC Form LU-1:  Project Summary & Evaluation for Use of Class 3B and Class 4 Lasers and Laser Systems (New/Amend Project Form), with SOPs attached. Form LF-1:   Laser Facility Approval Request (New Lab Application) Form LS-1: Laser Registration Form LU-2:  Application to Use Class 3B and Class 4 Lasers and Laser Systems (New User Application)

Project Approval Process (2) Training must be completed by all restricted and unrestricted users. The LPI is not exempt. LSO must perform an assessment of the facility. LPI will ensure all required engineering, administrative, and procedural control measures are in place.

Restricted vs Unrestricted Users Must always be under direct supervision of an authorized, unrestricted user May never work alone with the laser unit Not required to submit an LU-2 form or complete the classroom session Must receive unit specific training on the laser being used Must complete retraining every two years

Restricted vs Unrestricted Users Must submit an LU-2 form and complete the classroom session Must receive unit specific training on the laser being used Once all registration and training requirements are fulfilled, unrestricted users may work with the laser without supervision Must complete retraining every two years

New User Information New users can only be added to approved laser projects. New users must: Fulfill all training requirements Submit a completed LU-2 to the LSO LU-2 forms are only required for unrestricted users Restricted users are not required to complete an LU-2 form, however, they must still gain approval from the LPI to use the laser system Comply with the requirements established for the laser safety project and the Laser Safety Manual.

Module 8 Facility and Personnel Responsibilities Laser Safety Program & Provisions Personnel Responsibilities & Requirements In this module, we will discuss

ANSI Z136.1-2007 Section 1: General Laser Safety Program Purdue University, as a facility utilizing Class 3B and Class 4 lasers, shall establish and maintain an adequate program for the control of laser hazards. Class 3B and Class 4 laser systems: overseen by Purdue University Laser Safety Program, all users must complete required training. Purdue University policy established by Executive Memorandum No. D-2 ANSI Z136.1-2007 Section 1: General

Laser Safety Program Provisions LSO has authority and responsibility to evaluate laser hazards, monitor and enforce compliance with required standards and regulations, and perform other specific duties and responsibilities. Education of authorized personnel in the safety use of lasers and laser systems. Application of adequate protective measures. ANSI Z136.1-2007 Section 1: General

Laser Safety Program Provisions (2) Incident investigation. Appropriate medical examination and surveillance. Formation of a Laser Safety Committee when the number, hazards, complexity, and/or diversity of laser activities warrants. ANSI Z136.1-2007 Section 1: General

Personnel Responsibilities Establish the safe use of the laser or laser system that is used. Inform LSO of any fabrication, altering, or installation of a Class 3B or Class 4 laser or laser system. Comply with the requirements as set forth by the ANSI Standard Z136.1 (2007) and Purdue University Laser Safety Guidelines. Different expectations for different personnel types Laser Principal Investigator (LPI) Employees working with lasers Other personnel ANSI Z136.1-2007 Section 1: General

Personnel Requirements Laser Principal Investigator (LPI) Issue appropriate instruction and training materials on laser hazards and their control to all personnel who may work with lasers that are operated within supervisor’s jurisdiction. Not permit the operation of a laser unless there is adequate control of laser hazards to employees, visitors, and the general public. Ensure all individuals working have submitted a completed LU-2 form, including LPI Ensure 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. ANSI Z136.1-2007 Section 1: General

Personnel Requirements Laser Principal Investigator (LPI) – cont’d For any known or suspected accident relating to a laser under his/her authority, enact appropriate response plan, which includes notification of the LSO. If necessary, assist in obtaining appropriate medical attention for any employee involved in a laser accident. Not permit operation of a new or modified Class 3B or Class 4 laser under his/her authority without LSO approval. Shall submit plans for Class 3B and Class 4 laser installations/modifications of installations to the LSO for review. Shall be familiar with the Standard Operating Procedures (SOPs) for each Class 3B and Class 4 laser under his/her authority, and ensure that that they are provided to all users of such lasers. ANSI Z136.1-2007 Section 1: General

Personnel Requirements Employees working with lasers Not energize or work with or near a laser unless authorized to do so by the laser’s supervisor. Comply with Purdue University Laser Safety Guidelines, LSO and LPI safety rules and procedures. Inform his/her LPI of any known or suspected accident involving a laser under their LPI’s jurisdiction. If the LPI is not available, notify the LSO. ANSI Z136.1-2007 Section 1: General

Medical Surveillance Practices General Information Module 9 Medical Surveillance Practices General Information In this module, we will discuss the general medical surveillance practices.

ANSI Z136.1-2007 Section 6: Medical Examinations General Information Medical surveillance must be performed as soon as possible, but no later than 48 hours of a suspected or actual laser-induced injury. Medical surveillance is encouraged for personnel using Class 3B and 4 lasers; surveillance may be ophthalmologic and/or dermatologic Dependent upon employee category (i.e. incidental personnel or laser personnel), the surveillance may be visual acuity or baseline as determined by ocular history. Frequency – should be performed prior to participation in laser work; shall be performed following suspected laser injury; periodic examinations are not required. For any suspected or actual laser-induced injury, medical surveillance must be performed as soon as possible, but no later than 48 hours. Medical surveillance is encouraged for personnel using Class 3B and 4 lasers. This surveillance may be ophthalmologic (or eye-related) and/or dermatologic (or skin-related). Dependent upon employee category (such as incidental personnel or laser personnel), the surveillance may be for visual acuity or to establish a baseline as determined by the individual’s ocular history. Medical surveillance is recommended prior to participation in laser work and is required following suspected laser injury. Periodic examinations are not required, but they are recommended. ANSI Z136.1-2007 Section 6: Medical Examinations

Required Training General Information Module 10 Required Training General Information In this module, we will discuss the laser safety program general training requirements.

ANSI Z136.1-2007 Section 5: Education and Training General Information Required for any employee routinely working with (unrestricted users) or potentially exposed to (restricted and unrestricted users) Class 3B or Class 4 laser radiation. Refresher training (online) is required at 2 year intervals. Trainer Qualifications – LSO or individual with training skills and knowledge including knowledge of lasers, laser safety concepts, and laser safety standards. LSO – multiple requirements; specialized training. User Training – Where appropriate, shall include CPR training and safety procedures for applicable non-beam hazards. Training records must be maintained by LSO regarding trainee information, date, and topics covered. The Laser Safety Training course is designed to instruct users of Class 3B and Class 4 laser systems on required topics as established by ANSI Z136.1 - 2007. In additional to this Blackboard course, there is an abbreviated classroom session that is mandatory for all Unrestricted Users and Laser Principal Investigators. If you are a Restricted User, you do not need to attend the classroom session. Once you complete these trainings, you must receive laser specific training from either your Laser Principal Investigator or a qualified Unrestricted User on the project for any laser that you will be using. There is a "Laser Safety Retraining" course that requires completion every 2 years for all users, and is also found in Blackboard. It may be necessary for you to take additional trainings dependent on the hazards involved. Find out from your supervisor what other trainings may be required. ANSI Z136.1-2007 Section 5: Education and Training

Consequences of Non-Compliance General Information Module 11 Consequences of Non-Compliance General Information In this module, we will discuss the general consequences of non-compliance.

General Information The LSO has the authority to suspend, restrict, or terminate the operation of a laser system if the LSO deems that controls are not adequate. LPIs, authorized users, and/or associated personnel found in non-compliance of the Purdue Laser Safety Program and/or applicable governmental regulations may be subject to review by the Laser Safety Committee, at a minimum. Penalties for non-compliance shall be determined by the Laser Safety Committee and/or other applicable bodies of authority. If the Laser Safety Officer determines that controls are not adequate for the protection of personnel or property, they have the authority to suspend, restrict, or terminate the operation of the laser system. LPIs, authorized users, or other associated personnel found in non-compliance of the Purdue Laser Safety Program and/or applicable governmental regulations may be subject to review by the Laser Safety Committee, at a minimum. Penalties for non-compliance shall be determined by the Laser Safety Committee and/or other applicable bodies of authority. Generally, willful violations are held under the most critical review.

Emergency Procedures Personnel Injury Fire Module 12 Emergency Procedures Personnel Injury Fire In this module, we will discuss what steps need to be taken in case of injury or fire.

Incidents/Emergencies PERSONNEL INJURY Turn off the laser system with the “Emergency Button” or power switch. If injured personnel require medical assistance, don appropriate Personal Protective Equipment (PPE, i.e. gloves), and provide minimum assistance, as needed. Ensure someone remains with the victim until medical personnel arrive. Contact medical personnel (call 911). Inform them of the accident and that lasers are involved. Contact REM (49-46371). Complete incident report. In case of PERSONNEL INJURY, turn off the laser system with the “Emergency Button” or power switch. If injured personnel require medical assistance, put on appropriate Personal Protective Equipment (such as gloves), and provide minimum assistance, as needed. For instance, if the victim received a laser burn, hand them a cold pack that they can apply themselves. Make sure someone remains with the victim until medical personnel arrive. Contact medical personnel by calling 911. Inform them of the accident and that lasers are involved. Then contact REM. An incident report and First Report of Injury will need to be completed.

Incidents/Emergencies FIRE Sound fire alarm. Contact fire department (call 911). Inform them of the incident. If fire has gone out, call the Purdue University Fire Department (PUFD) at the non-emergency number (49-46919) Turn off the laser system with the “Emergency Button” or power switch. Evacuate area. Contact REM (49-46371). Complete incident report. In case of FIRE you should immediately sound the fire alarm and contact the fire department by calling 911. Inform them of the incident. If fire has gone out, call the Purdue University Fire Department at their non-emergency number – they will still need to verify that the fire no longer exists, and determine the cause of the fire. If fire has not gone out, turn off the laser system with the “Emergency Button” or power switch and evacuate the area. Once safely evacuated, contact REM. An incident report will need to be completed.

Contact Information Zach Tribbett, Laser Safety Officer 494-1478 ztribbet@purdue.edu Jerry Gibbs, Laser Training and Authorization Information 494-0207 jjgibbs@purdue.edu Other Radiation Safety Staff: 494-6371 For further information, please feel free to contact Purdue’s Laser Safety Officer, Mary Handy. If Mary is unavailable, please contact the Director of Radiological and Environmental Management, Jim Schweitzer. If you simply need some general information, or to schedule training, please phone the general office number for the Dept. of Radiological and Environmental Management, at 765-494-6371.

Test and Classroom Session The link to the examination is included on the next slide. Once you have completed the test, you will receive an email indicating whether or not you have passed. If you pass, and have indicated that you wish to become an unrestricted user, the confirmation email you receive will include a link to the online registration for the classroom session. If you pass, and have indicated that you wish to become a restricted user, you will receive a confirmation email detailing the responsibilities of a restricted user. An email will also be sent to your LPI notifying them that you wish to join their project. You must provide your LPI’s correct email address. The email will only be sent if you pass. They will not be notified of a failed exam.

Click here to begin the test. Complete the test indicated below. You must have a minimum score of 75% to pass. Your results will be sent to you through email, and, if you have passed, will be the documentation you would use to prove certification for renewal. You will need to complete a test to indicate successful completion. A passing grade is 75% or more of correct responses. Your results will be sent to you via email. Click here to begin the test.