University of Illinois at Urbana-Champaign, Exams of Optics

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University of Illinois at Urbana-Champaign Laser Safety Manual Emergency reference numbers: Police, Fire, or Ambulance…………………….9-911 from campus phone Radiation Safety……………………………217-333-2755 Laser Safety Officer…………………………217-244-7605 Revision 3 May 2014 Laser Safety Manual TABLE OF CONTENTS 1.0 Introduction ................................................................................................................. 2 2.0 Registration of Laser Systems ................................................................................... 2 3.0 Laser Safety Training Requirements ........................................................................ 3 4.0 Responsibilities ............................................................................................................ 4 4.1 PRINCIPAL INVESTIGATORS ............................................................................. 4 4.2 OPERATORS ........................................................................................................... 4 4.3 LASER SAFETY OFFICER .................................................................................... 4 4.4 DIVISION OF RESEARCH SAFETY PERSONNEL ............................................ 5 4.5 LASER SAFETY COMMITTEE ............................................................................. 5 5.0 Laser and Laser System Hazards .............................................................................. 6 6.0 Laser Classifications ................................................................................................... 7 7.0 Control Measures ...................................................................................................... 11 8.0 Emergencies and Incident Procedures .................................................................... 15 Appendix A: Recommended Laser Forms .................................................................. 18 Appendix B: SOP PREPARATION GUIDE ................................................................ 23 Appendix C: SAMPLE LASER SOPs .......................................................................... 25 Appendix D: Glossary ................................................................................................... 39 Appendix E: References ................................................................................................ 42 i 2.0 Registration of Laser Systems The Illinois Emergency Management Administration (IEMA) requires that all Class 3b or 4 laser systems be registered with the state. The Division of Research Safety (DRS) can assist with this registration process. To register a laser, obtain a copy of the Laser Registration from Appendix A of this manual. Provide full and complete responses to the application and submit it to the DRS. DRS will ensure that the laser system is registered with IEMA. University of Illinois Laser Safety Manual Revision Date: May 2014 Page 2 3.0 Laser Safety Training Requirements Each principal investigator (PI) is responsible for providing laser safety training to employees using lasers or entering controlled areas under his or her supervision. Other individuals may provide the training under the supervision of the PI. DRS can provide general training to personnel upon request. The nature of the initial laser safety training shall include instructions for the safe operation of each laser. Annual laser safety training is required. This training can be given as in-service training covering laboratory-specific laser safety techniques and information. Suggested topics: operation and emergency procedures, use of protective devices (including selection and use of eyewear), precautions to avoid exposure greater than the maximum permissible exposure (MPE) of a given laser, review of laser safety terminology. University of Illinois Laser Safety Manual Revision Date: May 2014 Page 3 4.0 Responsibilities 4.1 PRINCIPAL INVESTIGATORS The PI has is responsible for ensuring the safe use of laser. Specifically, PIs are responsible for ensuring that: • Only authorized individuals operate lasers or have access to controlled areas during laser operations; • Individuals authorized to use lasers have received adequate training; • Appropriate personal protective equipment (PPE) is available and worn when necessary; • Laser operating procedures are provided and include adequate safety measures; • Lasers manufactured or modified are properly classified, labeled and registered. • All class 3b and 4 lasers have been registered with Radiation Safety. • Details of any accidents/incidents involving lasers are provide to DRS in accordance with section 8.0 of this manual. 4.2 OPERATORS Persons operating lasers are expected to: • Follow proper operating and safety procedures, • Perform only those operations authorized by the PI, • Restrict access to controlled areas during operations. 4.3 LASER SAFETY OFFICER An individual designated as the campus laser safety officer (LSO) has the authority and responsibility to monitor and enforce the control of laser hazards and to effect the knowledgeable evaluation and control of laser hazards. The LSO is responsible for issuing laser incident/accident notifications and reports to the IEMA in accordance with section 8.0 of this manual. University of Illinois Laser Safety Manual Revision Date: May 2014 Page 4 6.0 Laser Classifications Lasers and laser systems are classified by potential hazard according to a system described in the American National Standards Institute (ANSI) standard Z136.1 and in 21 CFR part 1040. A laser’s classification is based on several factors, including its wavelength, power output, accessible emission level, and emission duration. The level of hazard associated with each class of lasers is listed below. Regulations in the United States define 5 laser classifications: Class 1, 2, 3A, 3B, and 4. These classifications currently dictate laser hazard standards in the US. International regulations define two additional classifications: Class 2M and 3R. Definitions provided for these classifications are for information only. CLASS 1 Lasers in this class cannot cause eye damage. These lasers are exempt from labeling requirements. CLASS 2 Lasers in this class emit visible light only. They are capable of producing eye damage only if the beam is stared at directly for longer than the normal human aversion response time to bright light (0.25 second). This means a person would naturally turn away from the beam before any damage is done. CLASS 2M A Class 2M laser is safe if not viewed through optical instruments; the blink reflex provides protection. This applies to laser beams with a large diameter or large divergence for which the amount of light passing through the pupil cannot exceed the limits for class 2. CLASS 3A Class 3a lasers are those that normally would not produce injury if viewed only momentarily with the unaided eye. They may present a hazard if viewed using collecting optics, e.g., telescopes, microscopes, or binoculars. CLASS 3R These laser products are marginally unsafe for intrabeam viewing (current Class 3A lasers that have beam diameters of less than 7 mm). A Class 3R laser is considered safe if handled carefully with restricted beam viewing, and the MPE can be exceeded with a low risk of injury. Visible continuous lasers in Class 3R are limited to 5mW. For other wavelengths and for pulsed lasers, other limits apply. CLASS 3B University of Illinois Laser Safety Manual Revision Date: May 2014 Page 7 Viewing of the direct or specularly-reflected beam from Class 3B lasers can cause eye damage. Diffuse reflections from these lasers are generally not hazardous except due to intentional staring at distances close to the diffuser. CLASS 4 Lasers in this class are high powered. Short-duration exposure to the direct, specularly reflected, or diffusely reflected beam can cause severe eye and skin damage. Flammable or combustible materials may ignite if exposed to the direct beam. EMBEDDED LASERS A laser system of one class may contain a laser of a higher class. For example, a class 3A system might contain a class 4 laser in an interlocked protective housing that incorporates design features to limit the accessible emission level to the class 3A level. If a laser or laser system has been manufactured by or modified at the U of I, the PI is responsible for determining the laser’s proper classification. This classification may be accomplished using one of the following tables (taken from ANSI Z136.1 -- 2000), depending on whether the laser is pulsed or continuous. University of Illinois Laser Safety Manual Revision Date: May 2014 Page 8 Classification Table for Continuous Wave (CW) Small-Source Lasers Wavelength (μm) Laser type Wavelength (μm) Class 1* (W) Class 2* (W) Class 3** (W) Class 4* (W) Ultraviolet 0.180 to 0.280 Nd:YAG (Quadrupled) 0.266 <9.6 x 10-9 for 8 hours None >Class 1 but <0.5 >0.5 Argon 0.275 Ultraviolet 0.315 to 0.400 He-Cd 0.325 <3.2 x 10-6 None >Class 1 but <0.5 >0.5 Argon 0.351, 0.363 Krypton 0.3507, 0.3564 Visible 0.400 to 0.700 He-Cd 0.4416 only <4 x 10-5 > Class 1 but <1 x 10-3 > Class 2 but <0.5 >0.5 Argon (visible) 0.457 <5 x 10-5 0.476 <1 x 10-4 0.488 <2 x 10-4 0.514 <4 x 10-4 Krypton 0.530 Nd:YAG (doubled) 0.532 He-Ne 0.543 Dye 0.400 - 0.500 <0.4CB x 10-4 He-Se 0.460 - 0.500 Dye 0.550 - 0.700 <4 x10-4 He-Ne 0.632 InGaAIP 0.670 Ti:Sapphire Krypton 0.6471, 0.6764 Near Infrared 0.700 to 1.400 GaAlAs 0.780 <5.6 x 10-4 None > Class 1 but <0.5 >0.5 GaAlAs 0.850 <7.7 x 10-4 GaAs 0.905 <9.9 x 10-4 Nd:YAG 1.064 <1.9 x 10-3 He-Ne 1.080 <1.9 x 10-3 1.152 <2.1 x 10-3 InGaAsP 1.310 <1.5 x 10-2 Far Infrared 1.400 to 1000 InGaAsP 1.550 <9.6 x 10-3 Holmium 2.100 Erbium 2.940 Hydrogen Fluoride 2.600 - 3.00 He-Ne 3.390 only Carbon Monoxide 5.000 - 5.500 Carbon Dioxide 10.6 Water Vapor 118 <9.5 x 10-2 Hydrogen Cyanide 337 * Assumes no mechanical or electrical design incorporated into laser system to prevent exposures from lasting to Tmax = 8 hours (one work day); otherwise the Class AEL could be larger than tabulated. ** Class 3a lasers and laser systems include lasers and laser systems that have an accessible output between one and five times the Class 1 AEL for wavelengths shorter than 0.4um or longer than 0.7 um, or less than five times the Class 2 AEL for wavelengths between 0.4 and 0.7 um. University of Illinois Laser Safety Manual Revision Date: May 2014 Page 9 CONTROL OF AREA Except for fully enclosed and interlocked systems, an authorized user must be present or the room kept locked during laser operations. INTERLOCKS Many laser systems have interlocked protective housings that prevent access to high-voltage components or laser radiation levels higher than those accessible through the aperture. These interlocks should not be bypassed without the specific authorization of the PI. Additional control measures should be taken to prevent exposure to the higher radiation levels or high voltage while the interlock is bypassed. PERSONAL PROTECTIVE EQUIPMENT Eye protection designed for the specific wavelength of laser light should be available and worn when there is a chance that the beam or a hazardous reflection could reach the eye. The manufacturer should mark protective eyewear with the wavelength range over which protection is afforded and the minimum optical density within that range. Eyewear should be examined prior to each use and discarded if there is damage that could reduce its effectiveness. Protective eyewear generally will not provide adequate protection when viewing the direct beam of a high-powered laser. Wearing protective eyewear should not be used as an excuse for performing an unsafe procedure. Eyewear is a laser safety necessity and must be maintained properly. Proper care of laser safety eyewear will prolong its life and help ensure that personnel are protected. Use a lens cleaning solution and cloth that are safe to use with the filters to remove dirt, oil, and dust without scratching, delaminating, or damaging dielectric coatings. Store eyewear in a hard or soft case and place in a secure area. These simple steps will keep protective equipment functioning properly for a long time. Each lab shall inspect laser safety eyewear at least every six months to ensure that there are no scratches, holes, cracks, pits, discolorations, or other damage that would reduce the intended safety level. Eyewear found to be unacceptable shall be removed from service. Results of this inspection shall be documented. TRAINING All operators must be trained by the PI, or person designated by the PI, in the safe and proper use of lasers before being allowed to operate a laser. Annual laser safety training is also required. All training should be documented. OPERATING PROCEDURES Written operating and specific alignment procedures that describe applicable safety measures should be available. University of Illinois Laser Safety Manual Revision Date: May 2014 Page 12 MAINTENANCE/SERVICE Only a knowledgeable person who has been specifically authorized by the PI to perform such work should perform maintenance, servicing, or repair of a laser. Whenever such work involves accessing an embedded laser of a higher class, the controls appropriate to the higher class must be applied. Any laser that is significantly modified must be re-evaluated to determine its classification. The following table provides general laser safety guidelines for all classes of lasers. University of Illinois Laser Safety Manual Revision Date: May 2014 Page 13 LASER SAFETY GUIDELINES CLASS USER PRECAUTIONS General Safety for All Classes • Ensure that personnel have had safety training appropriate to the level of expected hazard. • Do not aim the laser beam at people or at objects not involved in the research. • Protect against non-beam hazards. • Use the minimum energy required for the experiment. • Develop standard procedures (e.g., operating, alignment). 1 • No user rules necessary in normal usage. 2 • Do not stare into the laser beam. 3A • Permit only properly trained personnel to operate the laser. • Do not view the beam or its specular reflection with collecting optics. 3B • Establish a Nominal Hazard Zone (NHZ) for the laser. • Post appropriate laser hazard signs. • Permit only properly trained personnel to enter the NHZ and operate the laser. • Do not view the laser beam or its specular reflection. • Enclose as much of the beam path as possible. • Use beam stops to terminate beams at the end of useful beam paths. • Ensure that the beam path is above or below the eye level of sitting and standing personnel. • Mount the laser, its associated optics, and other equipment firmly to a stable surface to ensure that the beam travels along its intended path. • Wear appropriate laser eyewear within the NHZ. • Practice good laboratory hygiene. Remove unnecessary reflective surfaces from the vicinity of the beam path. 4 • Establish a Nominal Hazard Zone (NHZ) for the laser. • Post appropriate laser hazard signs. • Permit only properly trained personnel to enter the NHZ and operate the laser. • Do not view the laser beam, its specular reflection, or in some cases, its diffuse reflection. • Enclose as much of the beam path as possible. • Use non-flammable beam stops to terminate beams at the end of useful beam paths. • Ensure that the beam path is above or below the eye level of sitting and standing personnel. • Mount the laser, its associated optics, and other equipment firmly to a stable surface to ensure that the beam travels along its intended path. • Wear appropriate laser eyewear within the NHZ. • Practice good laboratory hygiene. Remove unnecessary reflective surfaces from the vicinity of the beam path. • Install appropriate shielding to protect personnel from the beam. • Operate the laser in a room with door interlocks if possible. • Use remote firing and/or remote monitoring systems if possible. University of Illinois Laser Safety Manual Revision Date: May 2014 Page 14 Reports A written report shall be made to the IEMA within 30 days for any of the exposures described in the preceding paragraphs. Each report shall include the full name of each individual exposed to laser radiation, including estimates of each individual’s exposure, levels of laser radiation involved, the cause of the exposure, a description of the injuries, and corrective steps taken or planned to be taken to prevent a recurrence. The report shall also be sent to the individual(s) exposed to laser radiation. The report to the individual shall be transmitted at a time not later than the date of transmittal to IEMA. Reports are normally prepared and transmitted by the DRS. WORKERS COMPENSATION: For information concerning workers compensation go to: http://www.obfs.uillinois.edu/risk/workers_compensation University of Illinois Laser Safety Manual Revision Date: May 2014 Page 17 Appendix A: Recommended Laser Forms University of Illinois Laser Safety Manual Revision Date: May 2014 Page 18 University of Illinois LASER REGISTRATION FORM Required for all class 3B or 4 lasers Complete this form and return to: Radiation Safety Section Division of Research Safety, MC-225 GENERAL INFORMATION – Please print legibly Principal Investigator_______________________________________ Department_______________________________________________ Office______________________ Phone________________________ Email________________________ Mail Code___________________ LASER SYSTEM DESCRIPTION Location of laser (room & building)_____________________________ Manufacturer______________________ Model__________________ Serial number_______________________ Class_________________ UIUC Property #___________________________________________ Status of unit: ___Operable ___Inoperable ___Stored Date placed in service:__________________ Laser type (CW, pulsed)_____________________________________ Description (He-Ne, Nd-YAG, CO2, etc)_________________________ Wavelength(s)____________________________________________ Maximum power (Watts) or energy (Joules)_____________________ Pulse duration (if applicable)___________, Frequency_____________ Emerging beam divergence__________________________________ Beam diameter____________________________________________ Has laser been modified from the original? ___Yes ___No Description of changes made____________________________ ___________________________________________________ S:\RSS\lasers\Laser Registration Form.doc University of Illinois Laser Safety Manual Revision Date: May 2014 Page 19 Laser Safety Training Record (for multiple-laser labs) Location:_____________________________ PI:______________________________________ Attach list of laser systems for this location. The PI shall provide initial and annual in-service training on laser safety for laser users. The training shall cover: operating and emergency procedures; use of protective devices, including selection and use of eyewear; warnings and precautions to avoid possible exposure to laser radiation in excess of the MPE; and safety regulations. Authorized Users Systems Authorized to Use Date of Training University of Illinois Laser Safety Manual Revision Date: May 2014 Page 22 Appendix B: SOP PREPARATION GUIDE This outline can be used as basis for preparing laser standard operating procedures (SOPs). The SOP should include all lasers in a given laser system, including alignment and pumping lasers. The SOP should be reviewed every two years and revised as needed. I. Introduction A. Location of laser/laser system (building, room) B. Map of area C. Description of each laser: 1. Classification a. Class 1, 2, 3A, 3B, or 4 b. Continuous wave, pulsed, Q-switched 2. Lasing medium 3. Beam characteristics (as applicable): a. Divergence b. Aperture diameter c. Pulse length d. Pulse frequency e. Maximum energy output D. Purpose/application of laser(s) II. Hazards A. Identify hazards present: 1. Laser beam(s) 2. Electrical 3. Chemical 4. Fire/explosion 5. UV light B. Hazard analysis III. Controls A. Engineering controls, e.g., interlocks, beam stops. B. Administrative controls, e.g., signs, LSOP, etc. C. Personnel Protective Equipment, e.g., laser eye protection, gloves. IV. Operating Procedures A. Equipment preparation B. Personnel Protective Equipment preparation C. Step-by-step protocol for laser system operation D. Shutdown procedures E. Special procedures: 1. Alignment 2. Safety checks 3. Maintenance V. Emergency procedures University of Illinois Laser Safety Manual Revision Date: May 2014 Page 23 A. Immediate actions B. Medical assistance C. Contact information VI. User Training A. Initial orientation/basic laser safety principles B. Annual/in-service training C. Laser safety during operations D. Maintenance and repair training, if applicable E. Documentation of training VII. Responsibility A. Supervisor (include emergency contact) B. Users and auxiliary personnel VIII. Miscellaneous A. Rules for visitors B. Rules for building service workers C. Other University of Illinois Laser Safety Manual Revision Date: May 2014 Page 24 • Any stray or unused beams are terminated by using beam stops or dumps. • The beam is enclosed as much as practical; the shutter is closed as much as practical during coarse adjustments; optics/optical mounts are secured to the table as much as practical; beam stops are secured to the table or optics mounts. Electrical The High Watt laser uses high voltage to excite the lasing gas mixture, so all maintenance to the internal components of the High Watt laser may be performed only by authorized repair technicians, and there must be more than one authorized user present for any maintenance operation that requires access to the internal components of the laser. Chemical • Corrosive and toxic gases are used as the lasing medium of the High Watt laser. Even in small concentrations, fluorine gas can be hazardous. In addition, ozone and nitrogenous gases may be created by high-power UV pulses. Ensure that the room ventilation is working properly before operating the laser. • The smell of fluorine (a sharp, pungent odor) indicates that the laser cavity or Swagelok tubing is leaking, provided the exhaust is within normal parameters. If fluorine is detected, the gas cylinder could be leaking. • Nitrile gloves shall be used when changing optics or using polishing powder on the laser windows. Be aware that some of the laser windows are coated on one side. Wear nitrile gloves when changing the halogen filter. • A new fill may be performed only by authorized users or qualified laser repair technicians. Pressure • All large compressed gas cylinders shall be securely fastened to the wall with Unistrut and chains or similarly approved assemblies. Small cylinders used for experiments shall also be securely fastened. • Do not adjust the laser cavity windows unless following the guidelines laid out in the alignment supplement. The laser cavity can be alternately pressurized or under vacuum and thus represents both an explosion and an implosion hazard. • The use of compressed gases shall be performed only through a regulator. • The laser cavity pressure shall not exceed 4000 mbar, and lasing will not be efficient under 3100 mbar. 4. Normal Operation Laser Startup • Remove all jewelry from fingers and arms (e.g., rings, watch, bracelet). If wearing a necklace, either remove it or ensure that it is secured between your shirt and body. • Wear appropriate clothing to protect hands and arms from excessive laser radiation. University of Illinois Laser Safety Manual Revision Date: May 2014 Page 27 • Remove all unnecessary equipment, tools, and combustible materials from near the beam path to minimize the possibility of stray reflections and non-beam accidents. • Ensure that all personnel inside the Nominal Hazard Zone are wearing appropriate laser safety glasses. - Verify that the wavelength is suitable for the laser in use. - Verify that the optical density (OD), as indicated by inscriptions on the lenses or frame of the glasses, is adequate. - Ensure that the glasses are in good condition (i.e., no deep scratches or cracks in lenses, good frame integrity). • Check for exposed wiring or electrical components. Be aware that high voltage capacitors have electrical potential long after they have been de-energized and unplugged. • Do not open the laser cover except under instructions from a knowledgeable person. Besides exposing high voltage electrical sources, removing the cover may expose users to secondary wavelengths that may be invisible and that fall outside the protection range of the selected eyewear. • Avoid having eyes (including when wearing safety eyewear) in the same optical plane as the beam. Generally, personnel should remaining standing while the laser is in operation. If personnel must be seated, provide tall stools that will keep the eyes above the plane of the optical table. • Assure that the chiller is turned on and cooling water is flowing to the laser. • Verify that the High Watt laser back panel indicates the laser is on. • Confirm that the beam path is set up by using the HeNe alignment laser so that a focused spot will land onto the exposed target in the chamber. • Confirm that the HeNe alignment laser is out of beam path. • Confirm that all beam enclosures are in place before the High Watt laser shutter is opened. • Warn all personnel near the NHZ by saying “Firing” before starting to 1) fire the laser or 2) open the laser shutter. • If necessary, use an energy meter to check the laser energy. • Close the laser shutter and take the energy meter out of the beam path. • Record the laser status in the laser logbook. When ready to begin the run, open the shutter and ensure that all safety enclosures, beam stops, and shields are in place. • During the run, ensure that the laser beam is striking the target by indirectly noting the plasma glow of the plume. Do not stare directly at where the focused spot hits the target. • Record any anomalous behavior in the laser logbook, and alert other users. • If there are warnings from the laser computer application, refer to the laser manual for University of Illinois Laser Safety Manual Revision Date: May 2014 Page 28 troubleshooting. Laser shutdown • When the run is finished, close the laser shutter and stop the laser computer from triggering. • After the last user of the day, disconnect the power from the laser. • Record pertinent details for the laser usage in the log book. • Allow the chiller to run for at least a few minutes following laser usage. Before leaving the lab, turn off the chiller. • Ensure that the beam enclosures are left in place. This ensures that the laser will be ready to go in a short time period for the next user and protects the next laser user and other personnel in the area from potential stray beam reflections. • Place dust covers over optics as necessary. Alignments Beam alignment requires work with an open beam and involves directing the beam toward a series of reflective or partially reflective surfaces, such as mirrors or lenses, so that it follows a predetermined path. Laser alignments may be internal or external. Internal alignments take place within the laser cavity or head and often place the work at increased risk of electrical accidents as well as primary beam exposure and ancillary wavelength exposure. The need for internal alignments usually arises because of problems associated with beam mode or power. External alignments are those that occur from the laser’s end window to a terminal target. A number of optical components (optics) arrayed in more or less complex configurations may be between these two locations. The need for external alignments occurs because of reconfiguration of the optical setup or replacement of components either within the laser head or in the open beam path. Perform alignments with a colleague. Review alignment operating procedures with your colleague and communicate at all times. Identify equipment and materials necessary such as safety eyewear, tools, power meter/detector, and beam stops prior to performing alignment. View beams indirectly. Use thermal paper to view the excimer laser beam and paper business cards to view the HeNe laser alignment beam. • Internal Alignment (with laser windows cleaning/replacement) - Place dielectric pieces (with holes through the middle) on the front and back in front of the windows. University of Illinois Laser Safety Manual Revision Date: May 2014 Page 29 • Receive and document annual laser safety training; • Sign the authorized user sheet to affirm that the above steps have been completed. No unauthorized personnel may enter the laser area during laser operation unless accompanied by an authorized user. All visitors should be briefed on proper safety protocol and should wear appropriate laser safety goggles located near the entrance. University of Illinois Laser Safety Manual Revision Date: May 2014 Page 32 The following was taken from the Illinois Administrative Code, Title 32: Energy, Chapter II: Division of Nuclear Safety, Subchapter b: Radiation Protection, Part 315 “Standards for Protection against Laser Radiation”, Appendix A. Standard Operating Procedures (SOPs) are governed by institutional policy and are developed, modified and maintained in accordance with the needs of individual facilities. Information relative to safety incorporated into these SOPs is gathered from a wide range of resources, including, but not limited to, the laser system manufacturer or distributor. This appendix contains examples of SOPs for issues associated with the use of laser systems. It is recognized that the safety needs of installations with multiple laser systems may be different from those facilities with a single laser system. The samples that follow cannot cover all situations or procedures; they are only intended as models that should be used to accommodate specific requirements. It is reasonable to expect that the manufacturer of the laser system shall supply safety information that can serve as the cornerstone for the generation of the SOPs. It is incumbent upon the operator to demand the information from the manufacturer. The availability of safety related information is facilitated by the FDA requirement that the manufacturer of laser products provide the user with adequate instructions for the safe operation and maintenance of all laser products. SAMPLE 1: Controlled Access to the Laser Room Purpose: To define the area in which control measures shall be applied and to describe the control measures necessary in order to maintain a safe environment for use of the laser system. Policy: Class 3b and Class 4 lasers shall be operated in areas where traffic flow and compliance with all safety procedures can be monitored. Procedure: 1) Appropriate warning signs shall be posted at eye level on all doors that access a room where a laser is to be operated. These signs shall state all required information and shall be removed when the laser is not in use. 2) Safety goggles labeled with the appropriate wavelength and optical density shall be available at the entry where each door sign is posted. 3) Glass windows shall be covered with shades or filters of appropriate optical density whenever a fiberoptic laser system is operational. University of Illinois Laser Safety Manual Revision Date: May 2014 Page 33 4) All safety procedures shall be followed during service, maintenance and demonstrations. 5) No one shall be allowed into a laser room unless properly authorized and protected. 6) The laser shall not be activated when it is necessary to open the door, if the controlled area extends to the doorway. 7) Laser keys shall be kept in a secured area and signed out only by those authorized to do so. SAMPLE 2: Ocular Safety Purpose: To prevent ocular injuries to personnel working with Class 3b and Class 4 lasers. Policy: Within the controlled area, all personnel shall adhere to appropriate eye protection procedures during all laser applications. NOTE: Under some conditions, the controlled area may include the entire room in which the laser procedure is performed. Under those conditions, the ocular safety procedures listed in this Sample 2 apply to the entire room. In health care facilities, ocular safety procedures shall also apply to the patient receiving laser treatment. All personnel involved in maintenance and demonstrations of laser systems shall follow all ocular safety procedures whenever a laser is in operation in the facility. Procedure: 1) Appropriate eyewear shall be worn by everyone in the controlled area while the laser is in operation. Appropriate eyewear consists of glasses or goggles of sufficient optical density to prevent ocular damage at the laser wavelength in use. Exception to this is the operator looking through an attached microscope with a lens that has the appropriate optical density for the laser in use. 2) Prior to use, the operator and ancillary personnel shall be responsible for selecting and examining eyewear for comfort, proper fit, and presence of labels describing both wavelength and proper optical density. 3) If eyewear is damaged, it shall not be worn and a report shall be made to the laser safety officer. 4) Contact lenses are not acceptable as protective eyewear. Prescription lens wearers shall use appropriate laser safety eyewear. University of Illinois Laser Safety Manual Revision Date: May 2014 Page 34 5) In-line filters with minimum 0.3 micrometers filtration shall be placed between wall suction and the fluid canister for: a) Suction line not connected to evacuator b) Procedures producing minimal plume c) Failure of evacuator before or during operation 6) Distal collection port shall be no more than 2 cm from impact site when practical. 7) All tubing, connectors, adaptors and wands will be changed between patients and disposed of according to biohazard procedures. III. Electrical Shock 1) During service or maintenance, precautions shall be taken against electrical shock that may be fatal. 2) Medical lasers shall be installed and operated in conformity with the National Electrical Code. SAMPLE 5: Work Practices for Optical Fiber Communications Systems (OFCS) Purpose: To recognize and effectively deal with a variety of potential hazards that may be present when working on an OFCS. Policy: Engineering controls shall not take the place of good work practices. Good work practices are essential to operating, servicing and maintaining OFCS, especially with higher power systems that utilize Class 3b and Class 4 lasers. Procedure: The following presents some basic guidelines when working on any OFCS. 1) Trained Personnel. Only authorized, trained personnel shall be permitted to install or perform service on OFCS containing Class 3b or Class 4 lasers. 2) Unterminated Fibers a) Do not view the end of a fiber with unprotected eye. Fiber should only be viewed with an indirect image converter or with a filtered optical instrument or optical density (OD) sufficient to reduce the exposure to levels below the appropriate MPE. University of Illinois Laser Safety Manual Revision Date: May 2014 Page 37 b) Always cover the ends of unterminated fibers with a splice protector, tape or end caps. 3) Splicing. Splicing on ribbon cables, fixed array cables or OFCS containing Class 3b or Class 4 lasers shall be de-energized or viewing systems incorporating personal protection shall be employed. 4) Installation and Testing. The laser source shall be first to be disconnected and last to be connected when installing and/or testing an OFCS. 5) Modifications. No modifications shall be made to the OFCS or associated equipment without management or supervision authorizations. Such modifications may alter the service group classification of the OFCS. 6) Labels. Any damaged or missing optical safety labels shall be reported immediately to the supervisor. 7) Other Hazards a) Use of protective guards or shields shall be used during splicing and cleaving operation to prevent direct injury from small lengths or particles of fiber. Proper disposal of fiber pieces avoids subsequent embedding in clothing or skin. b) Optical photocuring may present a UV or light source hazard. Protective filter lenses of the appropriate optical density shall be worn if viewing of the light source is probable. University of Illinois Laser Safety Manual Revision Date: May 2014 Page 38 Appendix D: Glossary Accessible Emission Level (AEL) The magnitude of laser radiation to which human access is possible. Usually measured in watts for continuous wave lasers and in joules for pulsed lasers. Accessible Emission Limit The maximum accessible emission level permitted within a particular class. Aperture An opening through which laser radiation can pass. This term usually refers to the opening on the laser (or a protective housing) where the beam is emitted. Aversion Response Movement of the eyelid or the head to avoid exposure to a bright light. For laser light, this response is assumed to occur within 0.25 second. Continuous Wave (CW) Laser A laser that has a continuous output for greater than or equal to 0.25 second. Controlled Area An area where the occupancy and activity of those within are subject to control and supervision for the purpose of protection from hazards. Diffuse Reflection A reflection where different parts of the beam are reflected over a wide range of angles, such as when hitting a matted surface. Divergence (φ) Divergence is the plane angle projection of the cone that includes 1-1/e (i.e., 63.2%) of the total radiant energy or power. The value of divergence is expressed in radians or milliradians. Embedded Laser A laser with an assigned class number higher than the classification of the laser system in which it is incorporated, where the system's lower classification is appropriate because of the engineering features limiting accessible emission. Enclosed Laser System Any laser or laser system located within an enclosure that does not permit hazardous optical radiation emission from the enclosure. Erythema Redness of the skin due to congestion of the capillaries. University of Illinois Laser Safety Manual Revision Date: May 2014 Page 39