UC San Diego SearchMenu

Laser Safety Program: Laser Hazard Classifications

Read about laser hazard classifications and requirements used in UC San Diego's Laser Safety Program.

Laser hazard classification is based on the ability of the primary laser beam to cause biological damage to the eye or skin during intended use. UC San Diego researchers must determine the hazard classification of each laser or laser system they obtain or fabricate.

UCSD's Laser Safety Program adheres to the American National Standards Institute (ANSI) Z136.1-2007 system of classifying continuous–wave (CW) lasers and single pulse lasers according to their relative hazards.

Controls required by UCSD's Laser Safety Program are determined by the hazard classification of a laser or laser system and how and where it will be used.

Follow the Laser Safety Program requirements below specified by hazard class:

Expand all

Class 1 and 1M

Class 1 and 1M lasers and laser systems are considered safe and incapable of producing damaging laser radiation levels during normal operation.

Example: CD/ DVD players

Class 1 and 1M lasers and laser systems are exempt from control under the Laser Safety Program.

Class 2 and 2M

Class 2 and 2M are low-powered lasers with an output of approximately 1 milliwatt (mW) of continuous wave. All class 2 lasers operate in the visible portion of the electromagnetic spectrum of 400–700 nanometers (nm).

Example: barcode scanners

Eye protection is usually afforded by aversion response and blink reflex (0.25 seconds). However, a class 2 laser beam could be hazardous if one were to intentionally expose the eye for longer than 0.25 seconds.

Class 2 and 2a lasers and laser systems are exempt from control under the Laser Safety Program.

Class 3

Class 3 lasers and laser systems can emit any wavelength and may be hazardous under direct and specular viewing conditions, but diffuse reflection is usually not a hazard. These lasers are usually not a fire hazard.

Class 3 lasers and laser systems are exempt from control under the Laser Safety Program.

Class 3R

Class 3R lasers operate at 1–5 mW of continuous-wave.

Example: laser pointers

Class 3R lasers and laser systems are exempt from control under the Laser Safety Program.

  • Best practice:

Class 3B

Class 3B lasers operate at 5–500 mW of continuous-wave. Specific control measures are required to prevent direct or reflected beam viewing.

Principal investigators must meet these requirements for class 3B use:

Class 4

Class 4 lasers and laser systems operate at greater than 500 mW (continuous), can emit any wavelength, and are considered an eye, skin, fire, and diffuse reflection hazard. The most stringent control measures have been established for these lasers.

Specific control measures to prevent eye and skin exposure to direct and diffusely reflected beam are required.

Principal investigators must meet these requirements for class 4 use:

Class to be determined

Manufacturers are required by the U.S. Food and Drug Administration to label lasers with a hazard classification. In cases where the laser class is unknown (e.g., if a researcher fabricates a laser or laser system), do the following:

  • Contact the EH&S Laser Safety Officer, (858) 822-2850, to evaluate and classify the laser system.

Expand all