Office of Security, Safety and Risk Management

Laser Classification

The basic approach of virtually all laser safety standards has been to classify lasers by their potential hazard based upon their optical emission. Then specify control measures which are commensurate with the relative hazard of the classification. Basically, the classification scheme is used to describe the capability of the laser or laser system to produce injury to personnel. The higher the classification, the greater the potential hazard.

Americal National Standards Institute Laser Classification

Class		Properties
1		Exempt lasers or laser systems that cannot, under normal operation conditions, produce a hazard.
2		Low power visible lasers or laser systems which, because of normal human aversion responses, do not normally present a hazard, but may present some potential for hazard if viewed directly for extended periods of time.
3a		Lasers or laser systems that normally would not produce a hazard if viewed for only momentary periods with the unaided eye. They may present a hazard if viewed using collecting optics.
3b		Lasers or laser systems that can produce a hazard if viewed directly. This includes intrabeam viewing or specular reflections. Except for the high power class 3b lasers, this class laser will not produce a hazardous diffuse reflection.
4		Lasers or laser systems that can produce a hazard not only from direct or specular reflection, but also from diffuse reflection. In addition, such lasers may produce fire hazards and skin hazards.

Since 1976 Federal law requires the manufacturer of lasers to provide the classification for all lasers produced. If the laser is changed by the user, the classification must be determined and made known to all users.