A comprehensive resource for safe and responsible laser use



Laser Classes


Lasers are classified based on their potential for causing injury — especially eye damage, since the eye is most susceptible to excess laser light.

There are four main classes for visible-beam lasers: Class 2, Class 3R, Class 3B and Class 4. The first two are relatively safe for eye exposure; the last two are hazardous. The chart below shows that the eye injury hazard increases as the laser’s power increases.

Arrow - eye injury hazard 878w
Click chart for larger view

The detailed information given below is for laser light that is visible -- between 400 and 700 nanometers -- and for an unintentional exposure of less than 1/4 second. Consult other sources for classifications of infrared and ultraviolet lasers, or other visible-light exposure durations.

Laser Classes (visible light only, unintentional exposure)


Spreadsheet - laser classes 870w
Click table for larger view

For more information about a particular class, click here: __ Class 2 __ Class 3R __ Class 3B __ Class 4

For information about laser classifications in general, see this page from Rockwell Laser Industries.