Laser Safety

TITLE: Laser Safety
REFERENCE: 1-1
ISSUED: 4/2000
EFFECTIVE: 4/2000
SUPERSEDES: None

1.0  Scope

Provides safe practices, policies, and procedures for operation of lasers and follows guidance established in ANSI Z136.1-1993 and OSHA 29cfr1926.54.

2.0  Definitions

2.1  Class 1
Does not emit laser radiation at known hazard levels. Users of Class 1 laser products are generally exempt from radiation hazard controls during operation and maintenance.

2.2  Class 2
Low power visible lasers that emit above Class 1 levels, but not above 1 mW. The human aversion reaction to bright light will protect a person from Class 2 laser hazards.

2.3  Class 2a
A special designation based on a 1000 second exposure that applies to lasers that are "not intended for viewing", such as a supermarket laser scanner. The upper power limit of a Class 2a laser is 4.0 µW. These are products whose emission does not exceed the Class 1 limit for an emission of 1000 seconds.

2.4  Class 3a
Intermediate power lasers that emit a continuous wave beam between 1 and 5 mW. Class 3a lasers are only hazardous from intrabeam viewing. Limited controls are recommended. Class 3a lasers that do not exceed 2.5 mW/cm2 must be labeled with a specified "CAUTION" logotype. Those Class 3a lasers exceeding 2.5 mW/cm2 must be labeled with a specified "DANGER" logotype.

2.5  Class 3b
Moderate power lasers that emit a continuous wave between 5 and 500 mW, pulsed at 10 J/cm2, or the diffuse reflection limit, whichever is lower. In general, Class 3b lasers are not a fire hazard and are not generally capable of producing a hazardous diffuse reflection except for conditions of intentional staring done at distances close to the diffuser. Specific controls are recommended.

2.6  Class 4
High power lasers with a continuous wave emission of 500 mW that are hazardous to view under any condition and are a potential fire hazard and skin hazard. Class 4 lasers require special controls both for their use and for entry into a Class 4 laser controlled area.

2.7  Embedded laser
A laser that has been totally enclosed inside a protective enclosure equipped with interlocks and/or labels on all removable panels or access doors.

2.8  Nominal Hazard Zones (NHZ)
The space within which the level of the direct, reflected or scattered radiation during normal operation exceeds the applicable maximum permissible exposure level. Controls are required to prevent exposures in the NHZ.

2.9  Laser Personnel
Employees and visitors who work routinely in laser environments.

2.10  Laser Control Area
An area established to control exposure of employees, visitors or the public to Class 3b or Class 4 laser radiation. The controlled areas may be permanent or temporary as needed. Elements of the controlled areas are referenced in ANSI Z136.1, Section 4.

3.0  Responsibilities

3.1  Management
Management shall (1) assign a Laser Safety Officer to monitor, evaluate and enforce the control of laser hazards; (2) provide adequate resources to control hazards posed by laser use.

3.2  Safety and Site Services Office (SASS)
The SASS office shall (1) conduct an annual evaluation of the laser safety program; (2) provide technical guidance to laser operators regarding hazard control; (3) arrange for training and medical evaluation as necessary for laser operators and employees working in laser areas; (4) provide laser warning signs as needed.

3.3  Laser Safety Officer
The LSO shall (1) classify or verify classification of lasers and laser systems used at UCAR facilities; (2) evaluate hazards of laser work areas, including the establishment of Nominal Hazard Zones; (3) assure the prescribed control measures are in effect, recommending or approving alternate control measures as necessary, periodically auditing the control measures in use; (4) approve standard operating procedures, alignment procedures, and other procedures that may be part of the requirement for administrative and procedural control measures; (5) recommend protective equipment, including eye wear, clothing and barriers; (6) approve the wording on area signs and equipment labels; (7) shall approve laser installation and modification of facilities and laser equipment prior to use; (8) assure that adequate safety education and training is provided to laser area personnel; (9) shall determine the personnel categories for medical surveillance; (10) investigate any accident resulting from laser use.

3.4  Employees
Employees shall (1) work with or around energized lasers only with supervisor approval; (2) comply with safety rules and regulations described in this procedure; (3) report any accident involving lasers to their supervisor or the LSO.

3.5  Supervisors
Supervisors shall (1) assure employees and visitors have been instructed on the hazards of working with lasers, and the proper procedures for operating lasers; (2) assure hazard control measures are used; (3) develop procedures for the safe operation, alignment and maintenance of class 3a, 3b and 4 lasers; (4) provide LSO with calculations identifying the Nominal Hazard Zone for Class 3b and Class 4 lasers and laser systems (5) provide a list of employees assigned to work with lasers to the LSO; (6) obtain LSO approval to operate new or modified laser systems; (7) report any accident involving laser use to the LSO.

3.6  Contractors
Contractors using lasers at UCAR facilities shall present a laser safety program to the LSO for approval prior to conducting work.

3.7  Visitors
Visitors shall comply with the requirements of this procedure as instructed by the host employee.

4.0  Procedures

4.1  Hazard Evaluation and Classification
Specific instructions on hazard evaluation and classification are found in ANSI Z136.1, Section 3.

4.1.1  Evaluate the laser or laser system's capability of injuring personnel, based on the maximum output available for the intended use.

4.1.2  Evaluate the environment in which the laser or laser system is used. Determine the Nominal Hazard Zone (NHZ) for all Class 3b and 4 lasers and laser systems. The NHZ will be used to determine placement of control measures.

4.1.3  Determine if other non-laser hazards exist. Some examples are: compressed gasses, cryogenic materials, toxic and carcinogenic materials - including target products, noise, explosion hazards from targets and elements of the optical train, ultraviolet emissions, electrical hazards, and flammability of beam enclosures.

4.2  Establish Control Measures
Specific instructions concerning establishment of control measures are found in ANSI Z136.1, Section 4.

4.2.1  Control measures needed for each class of laser or laser systems are referenced in ANSI Z136.1, Table 10, attached as Appendix 1.

4.2.2  Examples of Caution, Danger, and informational signs are attached as Appendix 2.

5.0  Training

Training is required for all individuals who use or service Class 3a, Class 3b, Class 4 lasers and laser systems. It is highly recommended for Class 2 lasers and laser systems. Training programs shall contain materials suggested in ANSI Z136.1.

6.0  Medical Surveillance

Medical surveillance is required for employees and visitors who have potential exposure to Class 3b and Class 4 lasers. Incidental personnel shall have an eye examination for visual acuity. Laser personnel shall receive an ocular history, test of visual acuity, macular function and color vision discrimination. If any of these tests are abnormal, the LSO, patient, and physician shall determine the need for examination of the ocular fundus with an ophthalmoscope.

Personnel who work with ultraviolet lasers shall have a skin examination.

Medical surveillance is performed before assignment to laser work, in the event of accidental exposure above the maximum permissible exposure level, and at termination from laser work at NCAR.

7.0  Miscellaneous

7.1  Recordkeeping
All pertinent records regarding the establishment of a laser safety program, inspections, medical evaluations shall be kept by the Health and Environmental Safety Services office.