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Review and Approval Authority
Page Omitted
Emergency Telephone Numbers
(to be completed by the Laboratory Supervisor)
Standard Operating Procedures Guidelines
Medical Consultation and Examinations
UM Emergency Evacuation Procedures
UM Workers' Compensation Reporting Procedure
Standard Operating Procedures
(to be supplied by the Laboratory Supervisor)
LASER Inventory Reporting Procedure
(to be supplied by the Laboratory Supervisor)
2. Paramaeters and Correction Factors
3. Limiting Apertures for Hazard Evaluation and AEL Determination
4. Measurement Apertures for Classification
5. Accessible Emission Limits for Continuous-Wave Lasers and Laser Systems
6. Accessible Emission Levels (Radiant Energy) for Single-Pulsed Laser and Laser System Classification
6A. Typical Laser Classification - Continuous-Wave (CW) Lasers
6B. Typical Laser Classification - Single-Pulse Lasers
6C. Intrabeam MPE for the eye for Selected CW Lasers
6D. Intrabeam MPE for the skin for slected CW Lasers
6E. Intrabeam MPE for the eye and Skin for Selected Pulse Lasers
7. Optical Densities Required for Intrabeam Viewing at Selected Laser Wavelengths
** All rights reserved. This text, or any part thereof, may not be reproduced in any form without written consent from the University of Maryland, College Park Department of Environmental Safety.
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This is a statement of official University policy to establish the process for maintaining occupational exposures to laser light within acceptable industry standards, as recommended by the American National Standard for Safe Use of Lasers, (ANSI) Z-136 as well as the Occupational Safety and Health Administration (OSHA) Guidelines for Laser Safety and Hazard Assessment.
The University is dedicated to providing safe and healthy laboratory facilities for students and employees. Laboratory administrators, managers, faculty, staff and students share responsibility for minimizing exposure to hazardous laser light, which for the purpose of this policy includes all laser light between 0.180 and 10.6 microns, inclusive.
The Laser Safety Plan (LSP) shall be implemented for all facilities at the University of Maryland, College Park (UM) where the referenced lasers are utilized for research, education and training, manufacturing, and other processes.
The LSP shall be reviewed on an annual basis and updated as necessary.
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Environmental Safety (Main Office) (301) 405-3960
(Biosafety, Environmental Affairs, Occupational Safety and Health, Radiation Safety, Risk Management)
Laser Safety Officer (301) 405-3985
(Program Consultation and Administration)
University Health Center Occupational Health (301) 314-8172
(Medical Consultation and Evaluation)
Workers' Compensation Office (301) 314-8171
Facilities Management, Work Control (301) 405-2222
(Repair of Facility Equipment Deficiencies, e.g.,
fume hoods, emergency eyewashes, ventilation, etc.)
Laboratory Supervisor(s): Business-hours # After-hours # ___________________ ________________ ______________ ___________________ ________________ ______________ Laboratory Personnel: Business-hours # After-hours # _________________ ________________ _____________ _________________ ________________ _____________ _________________ ________________ _____________
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A good SOP is one that is clearly stated and realistic in scope. The format of all SOPs should be consistent and should incorporate:
SOPs indicate the measures that will be used to reduce or prevent employee exposure to hazardous laser light, including engineering controls, and the use and maintenance of personal protective equipment.
SOPs include provisions for additional employee protection for work with particularly hazardous substances, including electrical connections, and high pressure gas vessel use.
SOPs also indicate circumstances under which certain laboratory procedures, operations, or activities require prior approval from the LS/PI before implementation (e.g. use of radioactive materials, bench top manipulations without engineering controls, night or weekend work performed alone, etc...)
An outline for SOPs or lasers may be found in Appendix III.
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Medical surveillance is recommended by current standards of practice and may be required by some research funding agencies for personnel using class IIIB and IV lasers. The LS/PI must determine whether their research project requires medical surveillance.
Those personnel who work routinely within a laser environment, and are protected by engineering, procedural, and administrative controls.
Cost of medical surveillance examinations are the responsibility of the researcher's department. The cost of emergency medical examinations is covered by worker's compensation insurance or an individual's health care insurance.
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Examples of events or circumstances which might result in hazardous exposure include:
The University has established procedures for responding to job-related injuries. These procedures should be followed in the event of hazardous exposure due to the use of hazardous lasers in the laboratory (See page 18). In the event of life threatening injuries or illnesses, the UM Emergency Dispatcher should be immediately notified by calling 9-1-1. Any injury or illness occurring as a result of work activities should be reported to the Workers' Compensation Office, immediately after the incident occurs or the injury is treated. All incidents of hazardous exposure, including their disposition, should be reported to the Laser Safety Officer.
The following information should be provided at the time that an employee is referred for medical consultation and/or examination:
A written report must be provided to the employer from a physician to whom the employee is referred for medical consultation or examination connected with hazardous exposure. The physician's report(s) should indicate ONLY the specific findings of diagnoses related to occupational exposure and should include the following information:
If the event is determined to require investigation, a formal exposure assessment will be initiated by the LSO.
An exposure assessment may include the following items:
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All employees must be provided with information and training regarding the hazards of the lasers in their work area. Employees should be informed of:
Training of laboratory workers in the guidelines of OSHA recommendations and ANSI standards should be conducted through coordination with the LSO, and DES. The LS/PI is responsible for training all laboratory workers on the specific operations, safety features, emergency procedures and SOPs which apply to their facility and laser(s) in use. Documentation of training must be maintained by the LS/PI, and original copies of training certificates provided to the LSO.
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Class IIIB laser controlled area guidelines:
Class IV laser controlled area guidelines, in addition to class IIIB controls the following guidelines pertaining to a class IV system:
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Selecting appropriate eyewear: The following factors should be taken into account when selecting the appropriate eyewear:
The equation for optical density is as follows:
OD = log10 [Ho /MPE]where
Ho = anticipated worst case exposure; expressed in units of W/cm2 for CW sources, and in units of J/cm2 for pulsed sources.MPE = maximum permissible exposure in identical units to Ho
Values for MPE are found in Table 1.Selected optical densities for some typical lasers may be found in Table 7.
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Doors must be placarded in the case of Class IIIB and IV lasers.
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The primary protection against accidental contact with energized conductors is by means of a barrier system.
Electrical safety requirements may be found in OSHA National Electric Code, NFPA 70.
The DES Lockout/Tagout (LOTO) Plan establishes a policy for control of hazardous energy. All employees of the University and contract workers servicing equipment that can be energized must comply with this plan. The LOTO Plan is available from DES and may be obtained by calling (301) 405-3960.
Laser Generated Air Contaminants (LGACS):
The LS/PI should consider the possible exposure to LGACs. These may include but are not limited to:
Exposure criteria may be found in 29 CFR 1910 part Z as well as threshold limit values for chemical substances by the ACGIH. Additional information may be found by consulting Material Safety Data Sheets.
Other considerations include the need for:
The DES Occupational Safety and Health (OSH) section investigates potential exposures to air contaminants. Where there is a potential for the generation of LGACS, the employee shall call DES for information and assistance at (301) 405-3960.
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Recommended reference sources concerning safety operations with lasers include:
Safety with Lasers and Other Optical Sources
Plenum Press
American National Standard for Safe Use of Lasers
Laser Institute of America
OSHA Instruction PUB 8 - 1.7
OSHA
Journal of Laser Applications
Chapman and Hill
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Notify (301) 405-2222 Immediately for service or repair to fire protection systems.
A current copy of the UM Policy Concerning Fire Emergencies can be found on the UM Mainframe (INFORM). From the main menu select Campus Information; then select Departments and Services; then select Environmental Safety; then select UM Policy Concerning Fire Procedures.
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Worker-related injury and illness forms and information are distributed by the medical records personnel when the individual reports to the Health Center.
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Classification relates to the potential for the laser beam to cause injury and not from any ancillary hazards that may be present with the laser system.
ANSI, OSHA, and the CDRH classifications vary according to the class of laser. The following classifications are a general outline incorporating all 3 schemes. Specifics on the classifications may be found by referencing the standards and the regulations. These are available from the Department of Environmental Safety and the LSO.
Class I:
Class II:
Class IIA:
Class IIIA:
Class IIIB:
Class IV:
Specific classification tables for lasers may be found in the Appendix. CDRH classification may be found on the laser itself when purchased.
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MPE values are determined for the eye (intrabeam), for an extended source, and for the skin.
Accessible Emission Limit (AEL)
The Maximum Accessible Emission level permitted within a particular class.
AEL = MPE x (Area of Limiting Aperture)
Exposure Durations
Exposure duration times are used when determining the MPE levels for a laser hazard. The exposure durations are based on physiological and biological response times to exposures from sources of light in the case of the eye, and heat in the case of skin response.
Time (sec) Explanation
3 x 10 4 Occupational 8 hour work day.
86,400 Accumulate "ON" time for ultraviolet wavelengths over
24 hour period.
600 Visible wavelengths used for alignment.
10 For normal maximum exposure time, infrared wavelengths
due to natural body movements.
0.25 Normal eye aversion response to bright visible light.
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Wavelength Exposure Duration,t | MPE | Notes
(µm) (s) | (J·cm-²) | (W·cm-²) |
------------------------------------------------------------------------------
Ultraviolet
0.180 to 0.302 10-9 to 3x104 3x10-³ or 0.56t¼,
0.303 10-9 to 3x104 4x10-³ whichever is
0.304 10-9 to 3x104 6x10-³ lower.
0.305 10-9 to 3x104 10x10-³
0.306 10-9 to 3x104 16x10-³
0.307 10-9 to 3x104 25x10-³ See Tables 8
0.308 10-9 to 3x104 40x10-³ and
0.309 10-9 to 3x104 63x10-³ 9 for
0.310 10-9 to 3x104 0.1 limiting
0.311 10-9 to 3x104 0.16 apertures)
0.312 10-9 to 3x104 0.25
0.313 10-9 to 3x104 0.40
0.314 10-9 to 3x104 0.63
0.315 to 0.400 10-9 to 10 0.56 t¼
>0.315 to 0.400 10 to 3x104 1.0
Visible and Near Infrared
0.400 to 0.700 10-9 to 18x10-4 0.5x10-6 (See
0.400 to 0.700 18x10-6 to 10 1.8 t¾x10-³ Tables 8
0.400 to 0.550 10 to 104 10x10-³ and 9
0.550 to 0.700 10 to T1 1.8 t¾x10-³ for
0.550 to 0.700 T1 to 104 10CBx10-³ limiting
0.400 to 0.700 104 to 3x104 10CBx10-³ apertures)
0.700 to 1.050 10-9 to 18x10-6 0.5CAx10-6 For multiple
0.700 to 1.050 18x10-6 to 10³ 1.8CAt¾x10-³ pulses
0.700 to 1.050 10³ to 3x104 320CAx10-6 apply
1.050 to 1.400 10-9 to 50x10-6 5CCt¾x10-³ correction
1.050 to 1.400 50x10-6 to 10³ 9.0CCt¾x10-³ factor CP
1.050 to 1.400 10³ to 3 x 104 1.6CCx10-³ given in Table 6.
Far Infrared
1.400 to 1.500 10-9 to 10-³ 0.1 (See Tables
1.400 to 1.500 10-³ to 10 0.56t¼ for limiting
1.400 to 1.500 10 to 3x104 0.1 apertures)
1.500 to 1.800 10-9 to 10 1.0 For multiple
1.500 to 1.800 10 to 3x104 0.1 pulses apply
1.800 to 2.600 10-9 to 10-³ 0.1 correction factor
1.800 to 2.600 10-³ to 10 0.56t¼ Cp given
1.800 to 2.600 10 to 3x104 0.1 in Table6.
2.600 to 10³ 10-9 to 10-7 10x10-³
2.600 to 10³ 10-7 to 10 0.56t¼
2.600 to 10³ 10 to 3x104 0.1
========================================================================================
The MPE for diffuse reflections at wavelengths between 0.400 and 1.400 µm is obtained by
multiplying the corresponding MPEs above by CE. (See Table 6 and Figure 9 for correction factors and Tl.)
Notes: 1. For repeated (pulsed) exposures, see 8.2.2.
2. The wavelength region 
1 to 2 means 1 < < 2, e.g., 0.180 to 0.302 µm means 0.180 <= < 0.302 µm.
From ANSI Z136.1 (1993) Safe Use of Lasers, for complete information on laser safety, refer to the ANSI Z136 series of laser safety standards, contact Laser Institute of America at 1-800-34LASER for additional information.
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Correction Factor Wavelength Figure*
(µm)
--------------------------------------------------------------------------------------------
T1 = 10 x 1020(-0.550) 0.550 to 0.700 9
CB = 1.0 0.400 to 0.550 9
CB = 1015(-0.550) 0.550 to 0.700 9
CA = 1.0 0.400 to 0.700 8a
CA = 102(-0.700) 0.700 to 1.050 8a
CA = 5.0 1.050 to 1.400 8a
CP = n-1/4** 0.400 to 1000 13
CE = 1.0 
< min 0.400 to 1.400 -
CE = /min min< <max 0.400 to 1.400 -
CE = ²/(maxmin) > max 0.400 to 1.400 -
CC = 1.0 1.050 to 1.150 8b
CC =1018(-1.150) 1.150 to 1.200 8b
CC = 8 1.200 to 1.400 8b
================================================================================================================
* See figures for graphic representation.
** For pulse repetition frequencies below
55 kHz (0.4 to 1.05 µm) and below 20 kHz (1.05 to 1.4 µm).
(See 8.2.2.2.)
Notes: 1. For wavelengths between 0.400 and 1.400 µm:
min = 1.5 mrad for t <= 0.7 s
min = 2 t3/4 mrad for 0.7 s < t <
10 s min = 11 mrad for t >= 10 s
max = 100 mrad (See figure 3 for graphical representation of min.)
2. The wavelength region 1
to 2 means 1 <= <
2, e.g., 0.550 to 0.700 µm means 0.550 <=
< 0.700 µm.
From ANSI Z136.1 (1993) Safe Use of Lasers, for complete information on laser safety, refer to the ANSI Z136 series of laser safety standards, contact Laser Institute of America at 1-800-34LASER for additional information.
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Aperture Diameter (mm)
Spectral Region Duration Eye Skin
(µm) (s)
-------------------------------------------------------------------
0.180 to 0.400 10-9 to 0.25 1.0 3.5
0.25 to 3 x 104 3.5 3.5
0.400 to 1.400 10-9 to 3 x 104 7.0 3.5
1.400 to 102 10-9 to 0.3 1.0 3.5
0.3 to 10* 1.5 t3/8 3.5
10 to 3 x 104 3.5 3.5
102 to 103 10-9 to 3 x 104 11.0 11.0
* Under normal conditions these exposure durations would not be used for hazard evaluation.
Note: The wavelength region 1 to 2 means 1
<= <2 µm, e.g., 0.315 to 0.400 µm means
0.315 <= < 0.400 µm.
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Spectral Analysis Duration Aperture Diameter
(µm) (s) (mm)
0.180 - 0.302 10-9 to 0.25 1.0
0.25 to 3 x 104 3.5
0.302 - 2.8 10-9 to 3 x 104 50.0**
2.8 - 102 10-9 to 0.3 1.0
0.3 to 10 *** 1.5 t3/8
10 to 3 x 104 3.5
102 - 103 10-9 to 3 x 104 11.0
* These apertures are used for the measurement of optical power or energy for purposes of laser classification (sec 3.3).
** When the laser output is intended to be viewed with optics (excluding ordinary eyeglasses) or the laser Safety Officer determines that there is a reasonable probability of accidental viewing with optics, a 50 mm aperture is used if the following conditions are met.
Otherwise, the limiting apertures for the eye and skin from table 8 apply. For the specific case of optical viewing with the beam collecting instruments, the apertures listed in Table 8 for hazard evaluation apply to the exit beam of the optical instrument. Therefore, the effective measurement aperture for UV lasers (0.302 to 0.400 µm) is 7 mm for pulsed lasers and 25 mm for CW lasers.
*** Under normal conditions, these exposure durations would not be used for classification.
Note: The wavelength region 1 to 2 means 1 <=
<2 µm, e.g., 0.315 to 0.400 µm means 0.315 <=
< 0.400 µm.
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Wavelength Emission
Range Duration Class 1 ** Class 2 *** Class 3 **** Class 4
(µm) (s) (W) (W) (W) (W)
----------------------------------------------------------------------------------------------------------
Ultraviolet
0.18 to 0.302 3 x 104 <= 9.6 x 10-9 -- > Class 1 but >0.5
0.302 to 0.4 3 x 104 <= 3.2 x 10-6 -- <= 0.5 depending >0.5
depending on wavelength on wavelength
(see table 5) (See Table 5)
Visible
0.4 to 0.7 3 x 104 <= 0.4 Cs x 10-6 > Class 1 > Class 2 but >0.5
(see table 5) but <= 1x10-3 <= 0.5
Near Infrared
0.7 to 1.05 3 x 104 <= 128 CA x 10-6 -- > Class 1 but >0.5
depending on wavelength <= 0.5 depending
(see table 5) on wavelength
(See Fig. 8)
10***** <= 3.9 x 10-4 to <= 1.9 x 10-2 -- Class 1 but <=0.5 >0.5
1.05 to 1.4 > 1000 <= 600 Cc x 10-6 -- Class 1 but <=0.5 >0.5
(see table 5)
10 <= 1.9 x 10-3 to <= 1.6 x 10-2 -- Class 1 but <=0.5 >0.5
Far Infrared
1.4 to 4 > 10 <= 9.6 x 10-3 -- Class 1 but <=0.5 >0.5
Submillimeter
4 to 102 > 10 <= 9.6 x 10-3 -- Class 1 but <=0.5 >0.5
102 to 103 > 10 <= 9.5 x 10-2 -- Class 1 but <=0.5 >0.5
===================================================================================================================
* Emissions duration >= 0.25 s.
** When the design or intended use of the laser or laser system ensures personnel exposures of less than 104 s in any 24-hour period, the limiting exposure duration may establish a higher exempt power level, as discussed in 3.23.
*** See 3.3.2.1 for explanation of Class 2a laser.
**** For 1 to 5 mW cw laser systems (Class 3a) see 3.3.3.1 and 3.3.3.2.
***** For laser not intended to viewed.
Note: The wavelength range 1 to 2 means 1 <=
<2, e.g., 0.18 to 0.4 µm means 0.18 <= < 0.4
µm.
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Wavelength Emission
Range Duration** Class 1 Class 3b Class 4
(µm) (s) (J) (J) (J)
---------------------------------------------------------------------------------------------------
Ultraviolet
0.18 to 0.302*** 10-9 to 0.25 <=1.9 x 10-6 >Class 1 but <=0.125 >0.125
0.302 to 0.4 10-9 to 0.25 <=1.9 x 10-6 >Class 1 but <=0.125 >0.125
<=2.5 x 10-4 >Class 1 but <=0.125 >0.125
Visible
0.4 to 0.7 10-9 to 0.25 <=0.2 x 10-6 >Class 1 but <=0.03 >0.03
<=0.25 x 10-3 >Class 1 but <=0.03 >0.03
Near Infrared
0.7 to 1.05 10-9 to 0.25 <=0.2 x 10-6 to 2 x 10-6 >Class 1 but <=0.03 CA >0.03 CA
<=0.25 x 10-3 to 1.25 x 10-3 >Class 1 but <=0.03 CA >0.03 CA
1.05 to 1.4 10-9 to 0.25 <=2 x 10-6 >Class 1 but <=0.15 >0.15
<=1.25 x 10-3 >Class 1 but <=0.15 >0.15
Far Infrared
1.4 to 102 10-9 to 0.25 <=80 x 10-6 >Class 1 but <=0.125 >0.125
<=3.2 x 10-3 >Class 1 but <=0.125 >0.125
Submillimeter
102 to 103 10-9 to 0.25 <=10 x 10-3 >Class 1 but <=0.125 >0.125
<= 0.4 >Class 1 but <=0.125 >0.125
==========================================================================================================
* There are no Class 2 single-pulsed lasers.
** See note in Section 8 for pulse widths less than 1 ns.
*** Wavelength dependent (See Table 5).
Note: The wavelength range 1 to 2 means 1 <= < 2, e.g., 0.18 to 0.4 µm means 0.18 <= < 0.4 µm.
From ANSI Z136.1 (1993) Safe Use of Lasers, for complete information on laser safety, refer to the ANSI Z136 series of laser safety standards, contact Laser Institute of America at 1-800-34LASER for additional information.
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Wavelength Laser Type Wavelength Class 1 Class 2 Class 3b Class 4
(µm) (µm) (W) (W) (W) (W)
---------------------------------------------------------------------------------------------------------------------------------
Ultraviolet
0.180 to 0.280 Neodymium:YAG 0.266 only <=9.6x10-9 --|
(Quadrupled) |-- -- Class 1 but <=0.5 >0.5
Argon 0.275 for 8 hours --|
Ultraviolet
0.180 to 0.280 Helium-Cadmium 0.325 only --|
Argon 0.351, 0.363 only |-- <=3.2x10-4 -- Class 1 but <=0.5 >0.5
Krypton 0.3507, 0.3564 only --|
Visible
0.400 to 0.700 Helium-Cadmium 0.4416 only --| --|
Argon (Visible) 0.457, 0.476, 0.488, | |
0.514, etc. | |
Krypton 0.530 | |
Neodymium:YAG 0.532 |-- <=0.4x10-6 |
(Doubled) | |
Helium-Neon 0.543 | |-- Class 1 but Class 1 but <=0.5 >0.5
Dye 0.400 - 0.550 | | <=1x10-3
Helium-Selenium 0.460 - 0.550 __| |
Helium-Neon 0.632 <=7x10-6 |
Dye 0.550 - 0.700 <=0.4x10-6 - 7x10-5 |
InGaAlP 0.670 <=2.4x10-5 |
Ti:Sapphire 0.670 <=2.4x10-5 |
Krypton 0.6471, 0.6764 <=1.1x10-5,3x10-5 --|
Near Infrared
0.700 to 1.400 GaAlAs 0.780 <=0.18x10-3 --|
GaAlAs 0.850 <=0.25x10-3 |
GaAs 0.905 <=0.32x10-3 |-- -- Class 1 but <=0.5 >0.5
Neodymium:YAG 1.064 <=0.64x10-3 |
Helium-Neon 1.080, 1.152 only <=0.64x10-3 |
InGaAsP 1.310 <=4.40x10-3 --|
Far Infrared
1.400 to 103 InGaAsP 1.550 --| --|
Holmium 2.100 | |
Erbium 2.940 | |
Hydrogen Fluoride 2.600 - 3.000 |-- <9.6x10-3 |
Helium-Neon 3.390 only | |-- -- Class 1 but <=0.5 >0.5
Carbon Monoxide 5.000 - 5.500 | |
Carbon Dioxide 10.6 __| |
Water Vapor 118 --|__ |
Hydrogen Cyanide 337 __| <=9.5x10-2 __|
============================================================================================================================================
* Assumes no mechanical or electrical design incorporated into laser system to prevent exposures from lasting to Tmax = 8 hours
(one workday); otherwise the Class 1 AEL could be larger than tabulated.
** See 3.3.3 for definition of Class 3a.
From ANSI Z136.1 (1993) Safe Use of Lasers, for complete information on laser safety, refer to the ANSI Z136 series of laser safety standards, contact Laser Institute of America at 1-800-34LASER for additional information.
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Wavelength Laser Type Wavelength Pulse Duration Class 1 Class 3b Class 4
(µm) (µm) (s) (J) (J) (J)
---------------------------------------------------------------------------------------------------------------------
Ultraviolet
0.180 to 0.400 Excimer (ArF) 0.193 20 x 10-9 <=1.9x10-6* <Class 1 but <= 0.125 >0.125
Excimer (KrF) 0.248 20 x 10-9 <=1.9x10-6* <Class 1 but <= 0.125 >0.125
Neodymium:YAG 0.266 20 x 10-9 <=1.9x10-6* <Class 1 but <= 0.125 >0.125
Quadrupled (Q-sw)
Excimer (XeCl) 0.308 20 x 10-9 <=4.3x10-6* <Class 1 but <= 0.125 >0.125
Nitrogen 0.337 20 x 10-9 <=3.6x10-6* <Class 1 but <= 0.125 >0.125
Excimer (XeF) 0.351 20 x 10-9 <=4.3x10-6* <Class 1 but <= 0.125 >0.125
Visible
0.400 to 0.700 Rhodamine 6G 0.450 - 0.650 1 x 10-6 <=0.2x10-6 <Class 1 but <= 0.03 >0.03
(Dye Laser)
Copper Vapor 0.510, 0.578 25 x 10-9 <=2x10-7 <Class 1 but <= 0.03 >0.03
Neodymium:YAG 0.532 20 x 10-9 <=2x10-7 <Class 1 but <= 0.03 >0.03
Doubled (Q-sw)
Ruby (Q-sw) 0.6943 20 x 10-9 <=2x10-7 <Class 1 but <= 0.03 >0.03
Ruby (Long Pulse) 0.6943 1 x 10-9 <=4x10-6 <Class 1 but <= 0.03 >0.03
Near Infrared
0.700 to 1.4 Ti:Sapphire 0.700 - 1.000 6 x 10-6 <=1.9x10-7 <Class 1 but <= 0.03 CA >0.03 CA
Alexandrite 0.720 - 0.800 1 x 10-4 <=0.76x10-6 <Class 1 but <= 0.03 CA >0.03 CA
Neodymium:YAG 1.064 20 x 10-9 <=2x10-6 <Class 1 but <= 0.15 >0.15
(Q-sw)
Far Infrared
1.4 to 10³ Erbium:Glass 1.540 10 x 10-9 <=7.9x10-3 <Class 1 but <= 0.125 >0.125
(Q-sw)
Co:Magnesium- 1.8 - 2.5 80 x 10-6 <=7.9x10-4 <Class 1 but <= 0.125 >0.125
Fluoride
Holmium 2.100 250 x 10-6 <=7.9x10-4 <Class 1 but <= 0.125 >0.125
Hydrogen Fluoride 2.600 - 3.000 0.4 x 10-6 <=1.1x10-4 <Class 1 but <= 0.125 >0.125
Erbium 2.940 250 x 10-6 <=5.6x10-4 <Class 1 but <= 0.125 >0.125
Carbon Dioxide 10.6 100 x 10-9 <=7.9x10-5 <Class 1 but <= 0.125 >0.125
(Q-sw)
Carbon Dioxide 10.6 1 x 10-³ <=7.9x10-4 <Class 1 but <= 0.125 >0.125
====================================================================================================================
* Assuming that both eye and skin maybe exposed, i.e., 1.0 mm beam (area of limiting aperture = 7.9 x 10-³ cm²).
From ANSI Z136.1 (1993) Safe Use of Lasers, for complete information on laser safety, refer to the ANSI Z136 series of laser safety standards, contact Laser Institute of America at 1-800-34LASER for additional information.
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Laser Type Wavelength Maximium Permissible Exposure Exposure Duration
(µ) (J · cm-²) (W·cm-²) (s)
----------------------------------------------------------------------------------------
Argon 0.275 3x10-³ -- 10 to 3x104
Helium-Cadmium 0.325 1 -- 10 to 3x104
Argon 0.351 1 -- 10 to 3x104
Helium-Cadmium 0.4416 -- 2.5x10-³ 0.25
Argon 0.488,0.514 10x10-³ --- 10 to 104
Argon 0.488,0.514 -- 0.2 >104
Helium-Neon 0.632 -- 2.5x10-³ 0.25
Helium-Neon 0.632 10x10-³ 1.0x10-³ 10
Helium-Neon 0.632 0.17 --- >453* to 104
Helium-Neon 0.632 -- 17x10-6 >104
Krypton 0.647 -- 2.5x10-³ 0.25
Krypton 0.647 10x10-³ 1.0x10-³ 10
Krypton 0.647 0.280 --- >871* to 104
Krypton 0.647 -- 28x10-6 >104
InGaAIP 0.670 -- 2.5x10-³ 0.25
GaAs 0.905 -- 0.8x10-³ >1000
Neodymium: YAG 1.064 -- 1.6x10-³ >1000
InGaAsP 1.310 -- 12.8x10-³ >1000
InGaAsP 1.550 -- 0.1 >10
Carbon-Dioxide 10.600 -- 0.1 >10
===============================================================================================
* T1: see Table 6 and Figure 9.
From ANSI Z136.1 (1993) Safe Use of Lasers, for complete information on laser safety, refer to the ANSI Z136 series of laser safety standards, contact Laser Institute of America at 1-800-34LASER for additional information.
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Laser Type Wavelength Maximium Permissible Exposure Exposure Duration
(µm) (J · cm-²) (W·cm-²) (s)
-------------------------------------------------------------------------------------
Argon 0.275 3x10-³ -- 3x104
Helium-Cadmium 0.325 1 -- 10 to 1000
Argon 0.351 1 -- 10 to 1000
Helium-Cadmium 0.4416 -- 0.2 >10
Argon 0.488 -- 0.2 >10
Argon 0.514 -- 0.2 >10
Helium-Neon 0.6328 -- 0.2 >10
Krypton 0.647 -- 0.2 >10
GaAs 0.905 -- 0.5 >10
Neodymium: YAG 1.064 -- 1.0 >10
Carbon-Dioxide 10.600 -- 0.1 >10
From ANSI Z136.1 (1993) Safe Use of Lasers, for complete information on laser safety, refer to the ANSI Z136 series of laser safety standards, contact Laser Institute of America at 1-800-34LASER for additional information.
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Maximum Permissible Exposure
(J · cm-2)
Laser Type Wavelength Pulse Duration
(µm) (s) Eye Skin
----------------------------------------------------------------------------------------
Excimer (ArF) 0.193 2 x 10-8 3 x 10-3 3 x 10-3
Excimer (ArF) 0.248 2 x 10-8 3 x 10-3 3 x 10-3
Excimer (ArF) 0.308 2 x 10-8 6.7 x 10-3 6.7 x 10-3
Excimer (ArF) 0.351 2 x 10-8 6.7 x 10-3 6.7 x 10-3
Ruby (Normal-pulsed) 0.6943 1 x 10-3 1 x 10-5 0.2
Ruby (Q-switched) 0.6943 5 - 100 x 10-9 5 x 10-7 0.02
Rhodamine 6G dye laser 0.500 - 0.700 0.5 -18 x 10-6 5 x 10-7 0.03 to 0.07
Nd:YAG (Normal Pulsed) 1.064 1 x 10-3 5 x 10-5 1.0
Nd:YAG (Q-switched) 1.064 5 -100 x 10-9 5 x 10-6 0.1
Carbon Dioxide 10.6 1 x 10-3 10 x 10-3 10 x 10-3
From ANSI Z136.1 (1993) Safe Use of Lasers, for complete information on laser safety, refer to the ANSI Z136 series of laser safety standards, contact Laser Institute of America at 1-800-34LASER for additional information.
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Optical Density
Wavelength Exposure Time: (s)
Laser Type (µm) Power 0.25 10 600 3 x 104
XeCl 0.308b 50 Watts --- 6.2 8.0 9.7
XeFl 0.351b 50 Watts --- 4.8 6.6 8.3
Argon 0.514 1.0 Watt 3.0 3.4 5.2 6.4
Argon 0.514 5.0 Watts 3.7 4.1 5.9 7.1
Krypton 0.530 1.0 Watt 3.0 3.4 5.2 6.4
Krypton 0.568 1.0 Watt 3.0 3.4 4.9 6.1
HeNe 0.633 0.005 Watt 0.7 1.1 1.7 2.9
Krypton 0.647 1 Watts 3.0 3.4 3.9 5.0
GaAs 0.840b 50 mW --- 1.8 2.3 3.7
Nd:YAG 1.064b 100 Watt (CW) --- 4.7 5.2 5.2
Nd:YAG 1.064b (Q-switched)a --- 4.5 5.0 5.4
========================================================================================
a Repetitively pulsed at 11 Hz., 12 ns pulses, 20 mJ/pulse.
b OD for UV & FIR beams computed using 1 mm limiting aperture which
presents a "worst case" scenario. All visible/NIR computations assume
7 mm limiting aperture.
--- Invisible beams; aversion response time does not apply.
Note: OD values obtained using ANSI Z-136.1 (1986) MPE criteria.
Taken from Laser Safety Officer Course, Rockwell Industries, 1994.
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