Brown University laser safety program provides guidance on the safe use of lasers. While all lasers and laser systems (Class 1, Class 1M, Class 2, Class 2M and Class 3R, Class 3B and Class 4) should be used with caution, the program's purpose is to specifically ensure that all Class 3B or Class 4 lasers are purchased, used, stored and disposed of properly.
Class 3B lasers produce light with an intensity that can exceed the maximum permissible eye exposure. Therefore, a user subject to direct eye exposure without eye-protection has a reasonable chance of sustaining serious eye damage. The range of rated power that qualifies as Class 3B for a continuous wave laser is 5 - 500 milliwatt (at wavelengths above 315 nm). Pulsed lasers are considered Class 3B up to an output of 125 millijoule in less than 0.25 second.
Class 4 lasers produce light with an intensity that is known to exceed the maximum permissible eye exposure limit. Therefore, direct eye exposure to a Class 4 laser, without suitable eye-protection, will certainly lead to serious eye damage. Continuous wave lasers are Class 4 if their rated power emission is greater than 0.5 watt. Pulsed lasers are Class 4 if their rated output is capable of exceeding 125 millijoule in less than 0.25 second.
Each Class 3B or Class 4 laser system must be registered with Environmental Health and Safety (EHS). Brown University personnel wishing to own a laser system should fill out a Laser Use Registration, and submit it for review to the campus radiation safety officer prior to use.
To learn more about high intensity light sources and non-ionizing radiation, click the 'Compliance' and 'Resources’ tabs to the left.
Laser Safety Manual
Brown University’s Laser Safety Manual describes the requirements for the use of Class 3B and Class 4 lasers. Laboratory supervisors who use a laser or laser system at Brown University are responsible for ensuring that a standard operating procedure (SOP) is provided to all Class 3B and Class 4 laser users. The manufacturer’s operating manual should be consulted as part of the SOP. Typically, the operating manual does not provide enough protocol information for a complete SOP. The campus radiation safety officer can help with guidance on writing an effective SOP.
As recommended by Occupational Safety and Health Administration, the Brown University Laser Safety Manual follows the voluntary consensus American National Standards Institute (ANSI) Z136.1 – 2022. A copy of the ANSI Standard is available for review at EHS, 118 Waterman Street, Providence.
For information on laser pointer safety, see the document Guidelines for Laser Pointers.
Radiation Safety Committee
The Brown University Radiation Safety Committee (RSC) serves as the official governing body for faculty, staff and students on all matters relating to the use of ionizing and non-ionizing radiation in research and teaching. The RSC is responsible for overseeing research and teaching registrations to ensure conformity with the American National Standard for the Safe Use of Lasers.