Laser Safety Manual

ARKANSAS STATE UNIVERSITY
POLICIES AND PROCEDURES
FOR LASER SAFETY
1.0 INTRODUCTION
Arkansas State University (A-State) is committed to the safety and well-being of its employees,
students, and affiliated workers and to complying with all national standards in the use of lasers
in its research and educational programs.
2.0 PURPOSE
The purpose of this manual is to ensure the safe use of lasers at A-State by identifying hazards,
providing medical surveillance, and providing laser safety training for individuals using lasers.
3.0 DEFINITIONS
ANSI. American National Standards Institute
Class 1 Laser. Low-power lasers and laser systems that cannot emit laser radiation levels
greater than the Maximum Permissible Exposure (MPE). Class 1 lasers and laser systems are
incapable of causing eye damage.
Class 2 Lasers. Visible, low power lasers or laser systems that are incapable of causing eye
damage unless they are viewed directly for an extended period (greater than 1000 seconds).
3. Class 3 Lasers. Medium-power lasers and laser systems capable of causing eye damage with
short duration (<0.25 s) exposures to the direct or specularly reflected beam. Includes Class 3a
and 3b lasers.
Class 3a Lasers. Lasers or laser systems that normally would not be hazardous if viewed for
only momentary periods with the unaided eye. They may present a hazard if viewed using
collecting optics.
Class 3b Lasers. Laser or laser systems that can be hazardous if viewed directly. This includes
intrabeam viewing or specular reflections.
Class 4 Lasers. High powered lasers and laser systems capable of causing severe eye damage
with short-duration (<0.25 s) exposures to the direct, specularly reflected, or diffusely reflected
beam. Class 4 lasers and laser systems are also capable of causing severe skin damage and
igniting flammable and combustible materials.
Laser System Groupings. Lasers and laser systems are grouped according to their capacity to
cause injury, and specific controls are then described for each group.1 Information on the label
1
Lasers manufactured after August 1, 1976, are classified and labeled by the manufacturer.
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must include class, the maximum output power, the pulsed duration (if pulsed), and the laser
medium or emitted wavelengths.
Maximum Permissible Exposure (MPE). The level of laser radiation to which a person may
be exposed without hazardous effect or adverse biological changes in the eye or skin. The criteria
for MPE for the eye and skin are detailed in Section 8 of ANSI Z136.1-2014.
MSDS. Material Safety Data Sheet – available on the EH&S homepage.
4.0 APPLICABILITY
The requirements and recommended details of this policy are applicable to all lasers used by AState employees, students, and unaffiliated workers in research and instructional laboratories
5.0 REGULATIONS
A-State has adopted the American National Standard for the Safe Use of Lasers: ANSIZ136.1-
2014. ANSI Z136.1-2014 is recognized as a minimum standard for laser safety. A copy of the
A-State Laser Safety Manual must be available in each department using Class 3b or Class 4
lasers. A copy of ANSI 2136.1-2014 or later applicable edition is available in the Radiation
Safety Office and in the Office of Environmental Health and Safety.
6.0 POLICY
6.1 Training

Only qualified and authorized personnel are permitted to operate a laser. All employees,
students, and/or unaffiliated workers who are required to operate lasers must read the Laser
Safety Policies and Procedures and receive initial and annual laser safety training. The Principal
Investigator determines the employee’s operational qualification from departmental or technical
training or other acceptable learning experience.
Before operating a Class 3 or Class 4 laser, or a Class 1 laser system that encloses a Class 3 or
Class 4 laser, a person must: review the Laser Safety Policies and Procedures. The Principal
Investigator or Lab Supervisor must provide a thorough review of the laser equipment to be used
and the standard operating procedures for the specific equipment to be used. S/he moreover
must ensure that a new user reads the operating and safety instructions furnished by the
manufacturer before operating the equipment.
6.2 Medical Surveillance
Most lasers are capable of causing eye injury to anyone who looks directly into the beam or
specular reflections. In addition, diffuse reflection of a high-power laser beams can burn exposed
skin, ignite flammable materials, and activate toxic chemicals that release hazardous fumes,
gases, debris, and radiation. The equipment and optical apparatus required to produce the lasing
action and control and direct the laser beam also introduce additional hazards associated with
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water, high voltage, high pressure, cryogenics, noise, radiation, and toxic gases. Consequently,
medical surveillance is required as follows:
• Individuals operating Class 1, 2, and 3a lasers are exempt from eye exams as are laser
users who terminate his/her work in the laser laboratory unless the employee has had a
know laser injury to the eye.
• Laser operators or individuals who will work in areas where there may be exposure to
laser radiation from a Class 3b or Class 4 laser are required to have had a baseline eye
examination two years prior to using the laser.
• An eye exam is required in the event of exposure or suspected exposure incident.
6.3 Exposure Incidents
If an exposure incident occurs, the LSO must be notified by the Principal Investigator or by the
person operating the laser. If the incident causes an injury or could potentially have caused an
injury, the person or persons who have received an exposure should inform their supervisors and
have eye exams performed. Contact the LSO for a doctor’s appointment. Laser Safety personnel
will conduct an investigation, and an incident report will be written.
6.4 Laser Hazards
Before appropriate controls can be selected and implemented, laser radiation hazards must be
identified and evaluated. It is the responsibility of the Principal Investigator who operates or
supervises the operation of the laser to correctly identify the class of the laser and apply the
concomitant controls. Refer to either ANSI Z136.1- 2014 or contact the LSO for additional
information.
Types of hazards include:
• Eye: Acute exposure of the eye to lasers of certain wavelengths and power can cause
corneal or retinal burns (or both). Chronic exposure to excessive levels may cause corneal
or lenticular opacities (cataracts) or retinal injury.
• Skin: Acute exposure to high levels of optical radiation may cause skin burns; while
carcinogenesis may occur for ultraviolet and near ultraviolet wavelengths.
• Chemical: Some lasers require hazardous or toxic substances to operate (i.e., chemical
dye, Excimer lasers).
• Electric shock: Most lasers produce high voltages that can be lethal.
• Fire hazards: The solvents used in dye lasers are flammable. High voltage pulse or flash
lamps may cause ignition. Flammable materials may be ignited by direct beams or
specular reflections from high power continuous wave (CW) infrared lasers.
• Water Hazards: In general, lasers are water-cooled, so flooding is a possibility. Hose
connections should be checked regularly.
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7.0 ROLES AND RESPONSIBILITIES
Responsibility for the administration of the safety standards contained herein rests with the
Chancellor of the University or the President's designee and is directly overseen by the Associate
Vice Chancellor for Research. The Laser Safety Officer (LSO) is responsible for the
implementation of the appropriate safety standards. The LSO shall be an individual with 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 laser program will be the
responsibility of Laser Safety Officer with oversight by Radiation Safety Committee (RSC). The
RSC will review and approve all principal investigators, laser registration forms, laser
acquisition forms, will operate a comprehensive laser safety program, and make policy
recommendations to the University administration.
Principal Investigators are responsible for:
• The immediate supervision of lasers in the laboratory.
• Providing, implementing, and enforcing the safety recommendations and requirements
prescribed in this program.
• Classifying and labeling all of their lasers.
• Completing a Laser Registration Form and sending it to the Laser Safety Officer.
• Training and documenting all employees who work with and around Class 2a, 2, 3a, 3b,
and 4 lasers in the safe use of lasers.
• Registering for the Medical Surveillance program for users of Class 3b and Class 4
lasers.
• Notifying the LSO immediately in the event of an exposure to a Class 3b or Class 4 laser.
Laser Operators are responsible for:
• Following laboratory alignment, operational, safety, and maintenance Standard Operating
Procedures.
• Reading additional safety instructions in laser equipment operators’ manuals.
• Keeping the Principal Investigator fully informed of any departure from established
safety procedures. This includes notification of an exposure incident.
• Reading the University’s Laser Safety Manual, and becoming familiar with its contents.
• Registering for the Medical Surveillance program for users of Class 3b and Class 4
lasers.
The Laser Safety Officer or his/her representative will:
• Maintain an inventory of all Class 3b and Class 4 lasers. Classify or verify classification
if necessary.
• Be responsible for hazard evaluation of laser work areas, including the establishment of
Nominal Hazard Zones.
• Approve standard operating procedures, alignment procedures and other control
measures.
• Provide consultative services on evaluation and control of laser hazards and worker
training programs.
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• Inspect all Class 3b and Class 4 lasers for compliance at least annually with ASU Laser
Safety Program. Ensure any required corrective action is taken.
• Suspend, restrict or terminate the operation of a laser or laser system without adequate
hazard controls, and advise Laser Safety Committee of such action.
• Approve wording on area signs and equipment labels.
• Maintain records required by various regulatory bodies. Ensure records are maintained of
medical examinations and training has been provided.
• Investigate incidents involving potentially harmful laser exposures.
The Laser Safety Committee will:
• Develop and promulgate policies and procedures regarding laser safety within the
university;
• Review and grant permission for, or disapprove, the use of laser equipment of Class 3 or
• higher for experimental, routine, or non-routine uses within the university from the
• standpoint of health and safety of experimenters, students, and staff, and the general
public;
• Recommend candidates to the Associate Vice Chancellor for Research for the position of
University Laser Safety Officer;
• Outline the duties of the Laser Safety Officer;
• Insure compliance with laser safety standards, including federal and state regulations, and
• non-regulatory standards as outlined in the American National Standards Institute (ANSI)
Z136 series of laser safety standards;
• Review annual reports from the LSO regarding personnel training records, laser hazard
control measures, laser safety inspections, and other matters concerning use and
operational hazards of lasers.
• Investigate alleged infractions of safety rules or improper use of laser equipment brought
to their attention by the radiation safety officer or other responsible personnel; and
recommend remedial action to correct such infractions.
:
8.0 PROCEDURES
8.1 Eye Protection
Principal Investigators and/or staff who operate or supervise the operation of a laser are
responsible for determining the need for laser eye protection for a particular laser. If required,
eye protection will be provided by the supervisor for staff and visitors to the area. The booklet
"Guide for Selection of Laser Eye Protection” produced by the Laser Institute of America may
provide assistance in eyewear selection. Check with your Principal Investigator or the LSO for a
copy.
8.2 Power Levels
The minimum laser radiant energy or laser power level required for the application should
always be used.
8.3 Beam Control
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To minimize direct eye exposure, observe these precautions:
• Do not intentionally look directly into the laser beam or at a specular reflection,
regardless of
• its power.
• Terminate the beam path at the end of its useful path.
• Locate the beam path at a point other than eye level when standing or when sitting at a
desk.
• Orient the laser so that the beam is not directed toward entry doors or aisles.
• Minimize specular reflections.
• Securely mount the laser system on a stable platform to maintain the beam in a fixed
position during operation and limit beam traverse during adjustments.
• Confine primary beams and dangerous reflections to the optical table.
• Clearly identify beam paths and ensure that they do not cross populated areas or traffic
paths.
• When the beam path is not totally enclosed, locate the laser system so that the beam will
be outside the normal eye-level range, which is between 1.2 to 2 meters from the floor. A
beam path that exits from a controlled area must be enclosed where the beam irradiance
exceeds the MPE.
8.4 Warning Signs for Low-Power Lasers
Post "CAUTION-LOW POWER LASER" signs at each entrance to the operating area. If the
laser has not been labeled by the manufacturer, attach a label to the laser with its classification
and relevant warning information. (Refer to the ANSI Z136.1-2014 for further guidance on
control measures for various classifications of lasers.)
8.5 Standard Operating Procedures for Class 3b and 4 Lasers
• All Principal Investigators are required to write standard operating procedures (SOP) for
all laser operations involving Class 3b and Class 4 lasers. The SOP must detail
alignment, operation, safety, and maintenance procedures. The SOP should be posted or
attached to the inside surface of the lab door. Other unusual operating circumstances
may require additional procedures. Contact the Laser Safety Officer for assistance.
• A log must be maintained showing periods of use, service, maintenance, and incidents.
• A laser classification label must be conspicuously affixed to the laser housing.
• Each entrance must be posted with a danger sign in accordance with ANSI Z136.1-2014.
• Entrances to laboratories with Class 3b or 4 lasers shall have a warning sign. And
• All protective enclosures that surround laser devices and high-voltage electrical sources
must be equipped with interlocks to prevent operation of the equipment when enclosures
are not in place. Interlocks must be tested monthly to ensure that they are operational.
Interlocks must be designed so that after they are actuated, the capacitor banks, shutters,
or power supplies cannot be re-energized except by manually resetting the system. A
written record must be kept of each test in the log book (see section 12.3).
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• The responsible individual in a laser area controlled by a warning light is permitted to
momentarily override (bypass) interlocks to allow access of authorized persons if all of
the following conditions are met:
o There is no laser radiation hazard at the point of entry.
o The necessary protective devices are worn by the personnel entering the area.
o An interlock bypass circuit is designed into the interlock control system.
o This bypass circuit must only be operated from inside the interlocked area. It must
delay no more than 15 seconds before shutting down the system.
• If interlocks are not feasible, the Principal Investigator may consider the use of alarms,
voice warnings, danger lights, door locks, key cards, or extensive security. The Laser
Safety Officer and the Laser Safety Committee must be consulted in choosing
alternatives to interlocks.
• Laser laboratories and controlled areas must be designed so that personnel can enter and
leave under emergency conditions.
• Lasers must have a master switch with a key or coded access that prevents use once the
key has been removed or a code has been entered. The key must not be left in the control
panel when he laser is not in use.
• An alarm, a warning light, or a verbal "countdown" command must be used during
activation and start up.
• Lasers must have a permanently attached beam stop or attenuator and emission delays.
• Laser-controlled areas shall be established which have limited access and shielding
sufficient to contain or direct scattered radiation. Access to the area during laser operation
requires the permission of the responsible operator.
• Class 3b and 4 infrared laser beams with a wavelength greater than or equal to 710 nm
must be terminated with fire resistant material.
• Securely fasten all mirrors, prisms, beam stops, etc. in the beam path. Ensure that the
laser is also securely fastened.
• Circuit breakers must be identified for each laser.
• The entire beam path of Class 3 and Class 4 lasers, including the target area, should be
surrounded by an enclosure equipped with interlocks that prevent operation of the laser
system unless the enclosure is properly secured. When total enclosure of the laser beam
path is not practical, both the non-enclosed laser beam and any strong reflections must be
terminated at the end of their useful paths using such devices as backstops, shields or
beam traps.
• Materials that diffusely reflect laser radiation must be used in place of specularly
reflective surfaces wherever possible.
• To minimize personnel exposure, specularly reflecting surfaces that are needed for
beampath control should be enclosed or shielded.
• Ultraviolet (UV) and infrared (IR) lasers that emit invisible beams require additional
• Controls including the following:
o Visual or audible beam-warning devices must be installed in areas where
personnel may be exposed to radiation in excess of the MPE. These warning
devices must be clearly identified and visible from all areas of potential exposure.
o Shielding must be installed that will attenuate UV radiation to levels below the
MPE for the wavelength being used.
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o Hazardous concentrations of by-products formed by the reaction of intense UV
radiation with materials in the area must be controlled.
o IR beam enclosures and backstops must be fabricated of IR-absorbent material
and must also be fire-resistant.
• Controlled laser areas must be surveyed by the user both initially and when beam path
changes are made to locate and identify direct and reflected beams that exceed the MPE.
Shielding may be required to limit unwanted radiation.
• Personnel must never look directly into any laser beam.
• High powered laser optical systems must never be aligned by direct beam viewing if
the radiant exposure or irradiance exceeds the MPE.
• Use low-power lasers, diffuse reflectors, image-retaining screens, exposed Polaroid film,
and other devices that will minimize eye exposure.
• Using optical systems such as cameras, telescopes, microscopes, etc., to view laser beams
may increase the eye hazard. Therefore, all collecting optics must incorporate suitable
means (such as interlocks, filters, or attenuators) to prevent eye exposures above the
MPE.
• Laser protective eye wear shall be worn whenever MPE levels may be exceeded.
However, it is good practice to always wear eye protection when lasers are in use. In
general, eye wear provides protection over a narrow range of the laser spectrum. Eye
wear designed for protection at one wavelength may afford little or no protection at
another wavelength. Consult eye wear manufacturers and the LSO for proper selection of
protective eye wear.
• Laser protective eye wear must be approved by the American National Standards Institute
(ANSI) and clearly labeled with optical densities and wavelengths for which protection is
afforded. Eye wear must be inspected periodically by the user for pitting and cracking of
the attenuating material, and for mechanical integrity and light leaks in the frame.
• Protection for the skin may be afforded through the use of clothing to cover normally
exposed skin areas.
• Protective equipment is no substitute for common sense and the use of good safety
practices.
• When lasers are to be left unattended, de-energize the power supplies or capacitor banks
and remove the keys from power switches or master interlocks to prevent unauthorized
activation of the equipment.
• The operation of unattended lasers is only allowed when a specific SOP has been written
and approved by the Principal Investigator and the Laser Safety Committee.
• Occasionally, it may be necessary to remove protective enclosures or override equipment
interlocks or other safety devices for service adjustments, maintenance, special training
exercises, etc. In these instances, a temporary controlled laser area must be set up.
Specific methods for handling situations of this type must be described in the SOP.
• Because the area will not have all the standard safety features, the SOP must describe
provisions for protecting personnel who could potentially be exposed.
• When the entire beam path is not fully enclosed, restrict access into the area to persons
wearing proper protective equipment. Make sure that all optical paths from the restricted
access area are adequately covered to prevent escape of laser radiation greater than the
MPE for the eye. Refer to the ANSI Z136.1-2014 and Table 10 of this manual for further
guidance on control measures for various classifications of lasers.
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8.6 Converting to a Class 1 Enclosed Laser
Any laser or laser system can be converted to a Class 1 enclosed laser by including all of the
following controls in the laser system design. These controls will effectively enclose the laser,
thus preventing personal contact with emitted radiation while permitting unrestricted access into
the area.
Approval must be obtained from the Laser Safety Committee in order to convert a Class 3b or
Class 4 laser to a Class 1 enclosed laser. Users of these converted Class 1 lasers must still
attend annual laser safety training.
• House the laser system within a protective enclosure to prevent escape of laser radiation
above the MPE.
• The protective housing must prevent personnel access to the laser system during normal
operations.
• Personnel entering the enclosure to perform maintenance or adjustment tasks must be
made aware of the higher risk laser class.
• Install safety interlocks wherever the protective enclosure can be opened, removed or
displaced. When activated, these interlocks must prevent a beam with a radiant energy
above the MPE from leaving the laser or laser system. Service adjustments or
maintenance work performed on the laser system must not render the interlocks
inoperable or cause exposure levels outside the enclosure to exceed the MPE, unless
work is performed in a laser area with limited access and appropriate safeguards,
supervision, and control.
• The protective enclosure and the laser system must be designed and fabricated so that if a
failure occurs, the system will continue to meet the requirements for an enclosed laser
operation.
• Modifications to commercial laser systems must be evaluated. Contact the LSO for an
evaluation. If the modifications decrease the safety controls, an SOP will be required.
• Attenuated Viewing Windows: Use viewing windows containing a suitable filter material
that will attenuate the transmitted laser radiation to levels below the MPE under all
conditions of operation.
• Label the enclosure with "CAUTION-ENCLOSED LASER” signs and attach a label
directly to the laser which gives the laser classification in the absence of the enclosure.
Make sure that the label can be seen immediately when the enclosure is opened.
8.7 Controlling Associated Hazards
Many chemical and physical hazards other than laser radiation can be found in the laser area that
must also be adequately controlled as follows:
• Electrical Equipment and Systems. Always be aware of the high risk of injury and fire
in laser operations because of the presence of electrical power sources. The installation,
operation, and maintenance of electrical equipment and systems must conform to existing
standards. Contact Environmental Health and Safety (EH&S) for assistance.
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• Lighting. Adequate lighting is necessary in controlled areas. If lights are extinguished
during laser operation, provide control switches in convenient locations or install a radiocontrolled switch. 3. Luminescent strips should be used to identify table and equipment
corners, switch locations, aisles, etc. When ambient light is not sufficient for safe egress
from a laser area during an electrical power failure, install emergency lighting.
• Ionizing and Non-ionizing Radiation. Laser operations may involve ionizing radiation
that originates from the presence of radioactive materials or the use of electrical power in
excess of 15kV. If radioactive material is present in the laser system, "CAUTIONRADIOACTIVE MATERIAL" sign must be prominently displayed. If X-rays are
generated a CAUTION-X-RAYS" sign must be prominently displayed. Microwave and
radio frequency (RF) fields may be generated by laser systems or support equipment.
Contact the Radiation Safety Office at 753-1093 to obtain an evaluation of these hazards
before starting an operation.
• Hazardous Materials. Bring only those hazardous materials into the laser area that are
needed for the operation. Do not allow laser beams and strong reflections to impinge on
combustible materials, explosives, highly flammable liquids or gases or substances that
decompose into highly toxic products under elevated temperatures, without providing
adequate controls. Conduct or sponsor tests that establish the effects of beam interactions
with hazardous materials. Test results can be used to determine safe parameters for laser
operation. All hazardous materials must be properly used, stored and controlled. Consult
Material Safety Data Sheets, and EH&S for additional information.
• Dyes and Solutions. Dye lasers normally use a lasing medium composed of a complex
fluorescent organic dye dissolved in an organic solvent. These dyes vary greatly in
toxicity, mutagenicity, and potential carcinogenicity. Most solvents suitable for dye
solutions are flammable and toxic by inhalation and/or skin absorption. Prepare and
handle dye-solutions inside a chemical fume hood. Wear a lab coat, eye protection and
gloves. Pressure-test all dye laser components before using dye solutions. Pay particular
attention to tubing connections. Install spill pans under pumps and reservoirs. Be alert to
contaminated parts. Keep dye-mixing areas clean. Obtain Material Safety Data Sheets
from EH&S for all dyes and solvents. And use in accordance with those instructions.
• Water. In general, lasers are water-cooled, so flooding is a possibility. Check hose
connections regularly