Laser Safety
Laser Registration
All Class 3b and 4 lasers must be registered with the MMC EHS Department. All users of class 3b and 4 lasers must completely fill out the Laser Registration Form and submit it to the EHS Department.
Authorized Use
Only qualified and trained faculty, staff or graduate students may operate Class 3b and 4 lasers. To be qualified, a laser operator must meet both the training requirements outlined below, and operational qualifications established by the responsible faculty member and/or Laser Safety Officer (LSO). MMC provides introductory laser safety training and can help provide additional training materials to assist LSO’s with facility-specific training that covers procedures specific to each laser. (Note that documentation must be maintained to verify that the site-specific training is provided.)
All persons who work in areas where Class 3b or 4 lasers are used must be provided with appropriate training and written safety instructions (Standard Operating Procedures), so that the user will be able to safely use the equipment and will know how to follow procedures that will protect themselves and others. It is the LSO, or responsible faculty member’s responsibility to make sure this training is provided for Class 3b and 4 lasers. Safety training must be provided before persons are permitted to operate lasers without supervision. Site-specific training for Class 3b and Class 4 laser users shall include a thorough review by a senior, knowledgeable individual who recognizes all hazards associated with each laser that a person may operate and the protection methods that are required for each laser. For personnel who work with Class 3b or 4 lasers, the training shall include basic instruction on the following topics:
1. The biological effects of laser radiation
2. The physical principles of lasers
3. Classification of lasers
4. Control of areas
5. Medical examination options
6. Basic safety rules
7. Use of protective equipment (includes direction on how to select proper eyewear)
8. Control of related hazards including electrical safety, fire safety, and chemical safety (handling and storage)
9. Emergency response procedures.
All persons who work in areas where Class 2 or 3a lasers are used should be provided with appropriate training and written safety instructions (Standard Operating Procedures), so that the user will be able to safely use the equipment and will know how to follow procedures that will protect themselves and others. It is the LSO, or responsible faculty member’s responsibility to determine whether this training is necessary for Class 2 and 3a lasers.
Laser Classification
Class 1 lasers are considered to be incapable of producing damaging radiation levels, and are therefore exempt from most control measures or other forms of surveillance. Example: laser printers.
Class 2 lasers emit radiation in the visible portion of the spectrum, and protection is normally afforded by the normal human aversion response (blink reflex) to bright light. These lasers may be hazardous if viewed directly for extended periods of time. Example: laser pointers.
Class 3a lasers do not produce injury under normal conditions when viewed for a very brief period with the unprotected eye. These lasers may present a hazard if viewed using collecting optics, e.g., telescopes, microscopes, or binoculars. (Example: HeNe lasers above 1 milliwatt but not exceeding 5 milliwatts radiant power).
Class 3b lasers can cause severe eye injuries when viewed directly or from specular reflection. A Class 3b laser is not normally a fire hazard, though in some circumstances flammable liquids could be ignited. Example: visible HeNe lasers above 5 milliwatts but not exceeding 500 milliwatts radiant power.
Class 4 lasers present an eye hazard from direct and diffuse reflections. In addition, such lasers can cause combustion of flammable materials and produce serious skin burns and injury from direct exposure.
NOTES: Retinal injuries can occur instantaneously with Class 3b and Class 4 lasers and the damage may be irreparable. Corneal burns from far-Infrared (IR) and ultraviolet (UV) lasers may also be irreparable. Class 4 beams may be of sufficient power intensities to penetrate through the sclera (white) of the eye and damage the retina and other structures; turning one’s head or not looking directly at the laser offers little or no protection to high power lasers. Lens damage may also be caused by the beam and by photochemical reactions from exposure to UV and blue frequencies.