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Section III

Laser Classification

Lasers and laser systems are classified based on their capability of injuring personnel.

  1. Lasers manufactured after August 1, 1976 are classified and labeled by the manufacturer. The Principal Investigator shall classify lasers and laser systems that are constructed or modified in the laboratory.
  2. There are five laser hazard classes:
    • 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.)
    • 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. The normal aversion response to bright light (blinking) protects the eye from a momentary exposure.
    • Class 3a lasers and laser systems have an accessible output between 1-5 mW and do not pose a serious eye hazard unless viewed through optical instruments.
    • Class 3b lasers and laser systems have an accessible output between 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.
    • 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 reflections and diffuse reflections. Class 4 lasers and laser systems also pose skin and fire hazards.

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