Non-ionizing Radiation (Lasers)
302. Non-ionizing Radiation (Lasers)
The University of Texas at Arlington (UTA) has established a Radiation Safety Program (Program) to provide controls and safety guidance relevant to research and educational activities involving radioactive material and radiation producing machines. This Program is established to meet the requirements of 25 Texas Administrative Code (TAC) 289.301, other applicable regulations and/or standards, and prudent safety practices. If any conflict occurs between this Program and the TAC, the latter shall prevail.
BMP
Knowledge of Standards, Regulations, and Practice Guidelines
- The state of Texas requires a Certificate of Registration for Lasers with the Texas Department of State Health Services (DSHS).
- DSHS carries the authority to issue citations and/or legal action for non-compliance.
- All class 3B and 4 lasers must be registered with the state through the EHS office.
- Most laser standards focus on the theoretical basis for safety and include a mathematical approach. Laser users should have a working knowledge of the technical material, including exposure limits, nominal ocular hazard area, optical density levels, maximum permissible exposure, classifications, etc.
- Standards are nonregulatory, but serve as a consensus document for best practices.
Authority and Responsibility
- The Laser Safety Program shall be administered under the authority of the Laser Safety Officer (LSO).
- The LSO shall have the authority to authorize, suspend, and specific conditions of use for all laser facilities at facilities or and/or areas administered by UT Arlington.
Classification
- Classification of lasers shall be in accordance with US Food and Drug Administration (FDA) or American National Standards Institute (ANSI) specification ANSI Z136.1 B and the Texas Administrative Code 289.301.
Registration
- Each Class 3B or 4 laser that is possessed, purchased, donated, or otherwise received by any person or entity at UT Arlington shall have a LDR on file with the LSO. The LDR shall be submitted to the LSO by the receiving party as soon as is practicable, but in no case longer than 10 days following receipt of the laser. Additionally, PIs who receive Class 3B or 4 lasers through inter- and intra-departmental transfer or loan are required to file a LDR within 10 days of the transfer or loan.
Identification of Hazards and Risks
- Improperly used laser devices are potentially dangerous. Effects can range from mild skin burns to irreversible injury to the skin and eye. The biological damage caused by lasers is produced through thermal, acoustical and photochemical processes.
- Power output, beam diameter, pulse length, wavelength, beam path, beam divergence and exposure duration are all features of a laser device that determine the capability for injury.
- Classification of lasers determines the potential for injury from the laser and is also used to determine control measures.
- Laser operators should understand and implement the concepts of maximum permissible exposure (MPE), accessible emission level (AEL), and nominal hazard zone (NHZ).
- All individuals working near a laser system are exposed to potential hazards created by the laser. Strong consideration should be given to the location and placement of the laser.
- Presence of other workers, access control, number and class of lasers, permanence of laser, and objects or surfaces that can reflect the beam are all factors that should be considered when determining location.
- Non-beam laser hazards to consider include electrical, explosion, compressed gasses, laser dyes and solvents, noise, fire hazards, laser generated air contaminants, x-ray radiation hazards, radio-frequency radiation hazards, mechanical, small space dangers, and ergonomic considerations.
Establishing and Implementation of Control Measures
- Exposure controls are critical for protecting workers, and they either remove hazardous conditions or place barriers between workers and hazards.
- Controlling exposures to occupational hazards is the fundamental method of protecting workers.
- Hierarchy of Controls
- Elimination – physically remove the hazard
- Substitution – replace the hazard
- Engineering controls – reduce exposure or isolate people from the hazard
- Administrative controls – change the way people work
- Procedural controls – define how work with specific types of hazards is conducted to minimize these hazards
- PPE – personal protective equipment protects the worker from hazards
- Engineering controls include key control, interlocks, beam housing, shutters
- Administrative controls include training, signage, procedures
- Master Switch
- applicable to all class 3B and 4 lasers
- shall be operated by key or by coded access
- Safety Interlocks
- applicable to all class 3B and 4 lasers
- must be present on any safety housing that ensures the laser radiation is not accessible above MPE limits
- Exceptions to interlock requirements must have prior approval from the LSO.
- Warning Systems
- each class 3B and 4 lasers shall provide visual or audible indication during the emission of access laser radiation.
- Indication shall occur prior to emission of radiation with adequate time to avoid exposure. All visible indicators should be visible through protective eyewear.
- Protective Eyewear
- PI shall provide unrestricted access to protective eyewear that meets the requirements of 25 TAC 289.301(t)(1).
- PI (LSO) shall ensure protective eyewear is appropriate for the laser specification requirements.
- No person shall operate a class 3B or 4 laser without protective eyewear specific to that laser.
- Must be worn for alignment and any time there is access to an open beam.
- Shall be examined at intervals not to exceed 12 months to ensure effectiveness.
- Protective eyewear that does not pass inspection shall be immediately discarded and replaced.
- Protective equipment such as beam stops, shields, safety interlocks, and warning lights shall be maintained in proper working condition and utilized when indicated to prevent harmful exposure.
- Windows shall be covered with a non-flammable barrier that attenuates the laser radiation below the MPE and prevents individuals entering the controlled area from exposure to radiation above the MPE immediately upon entry.
Controlled Access
- Regulations and standards dictate procedure for maintaining controlled access to areas with laser devices and can vary according to laser classification.
- Class 3B and 4 lasers shall only be operated in a controlled area.
- Each controlled area shall be posted conspicuously with signs as specified in 25 TAC 289.301(v).
- Access to the controlled area shall be controlled by a door, blocking barrier, screen, or curtain, which attenuates the laser radiation to below the MPE, and individuals who enter the controlled area, shall not experience radiation above the MPE immediately upon entry.
Laser Safety Officer (LSO)
- LSOs are responsible for the management and mitigation of risk and have the authority to ensure compliance with all policies, procedures, rules, and regulations.
- LSOs responsibilities include hazard evaluations, establishing control measures, approving policies and procedures, ensuring appropriate PPE is available and maintained in good condition, approval and/or application of signage and labels, ensuring training, conduct audits, and investigate all accidents and incidents.
Laser Laboratory Audit
- The LSO or LSS shall audit the laboratory containing the laser(s). The audit shall be performed at least annually and shall be performed prior to operating a laser for the first time after assembly, maintenance, or modification of the beam path, operating wavelength, or power level. Audit records shall be retained for inspection by the LSO.
- Audit covers door signage, laser light sign, “Notice to Employee” signage, emergency contact information, Laser Safety Manual, current regulations, special instructions, posted SOP, etc.