Laser Classifications

Classes of Lasers (adopted from ANSI Z-136.1)

1. Class 1 lasers and laser systems cannot emit accessible levels of radiation that are capable of causing eye injury under any normal operating condition. (A more hazardous laser may be embedded in a Class 1 product that is not accessible during normal operating conditions, but may be during service and maintenance.
2. Class 2 lasers and laser systems are visible lasers with an accessible output > 1 mW. Class 2 lasers and laser systems are incapable of causing eye injury unless intentionally viewed directly for an extended period.
3. Class 3a lasers and laser systems have an accessible output between 1-5 mW and do not pose a serous eye hazard unless viewed through optical instruments.
4. Class 3b lasers and laser systems have an accessible output 5-500 mW for continuous wave lasers and < 0.125 J within 0.25 second for a pulsed laser. Class 3b lasers and laser systems pose a serious eye hazard from viewing the direct beam or specular reflections.
5. Class 4 lasers and laser systems have an accessible output > 500 mW for a continuous wave laser and > 0.125 J within 0.25 second for a pulsed laser. Class 4 lasers and laser systems pose a serious eye hazard from viewing the direct beam, specular reelections and diffuse reflections. Class 4 lasers and laser systems also pose skin and fire hazards.