Laser Warning signs and Labeling

Principal Investigators who use lasers are responsible for ensuring that all lasers are appropriately labeled and warning signs are conspicuously displayed in locations where they will best serve to warn on-lookers.

The following requirements must be followed for proper labelling of lasers and posting of signs:

  • The signal word "Caution" must be used with all signs and labels associated with class 2 and some 3R lasers or laser systems.
  • A class 2 laser or laser system must be labeled with the warning "Avoid Long Term Viewing of Direct Laser Radiation." This label does not need the warning symbol or signal words but must be visible during operation and bear the designation "Class 2 Laser."
  • The signal word "Danger" and “the white triangle with the red exclamation mark” must be used with all signs and labels associated with class 3b and 4 lasers and laser systems.
  • Appropriate space must be left on all signs and labels to allow inclusion of pertinent information. Such information may be included during the printing of the sign or label or may be handwritten in a legible manner to include the following:

Above the tail of the sunburst, the following special precautionary instructions or protective actions may be required for individuals entering the area:

a. For class 2 - "CAUTION - Laser Radiation - Do Not Stare Into Beam"

b. For class 3R - "DANGER - Laser Radiation - Do Not Stare Into Beam or View Directly With Optical Instruments"

c. For class 3B - "DANGER - Laser Radiation - Avoid Direct Exposure to Beam"

d. For class 4 - "DANGER - Laser Radiation - Avoid Eye or Skin Exposure to Direct or Scattered Radiation"

- Above the tail of the sunburst, precautionary instructions or protective actions to be taken by the reader should be provided such as "invisible beam, knock before entering, do not enter when light is on, restricted area, etc."

- Below the tail of the sunburst, the type of laser (e.g., Ruby, Helium-Neon, etc.) or emitted wavelength, the pulse duration if appropriate, and the maximum output must be provided.

- At the lower right, the class of the laser or laser system must be provided.

Back to top