Laser Classes & Divisions

Lasers are classified by the potential of the laser beam to cause injury. It takes into account the amount of the laser beam that you can get access to when the laser beam is in normal use or during maintenance.

Class 1 (I) Lasers:

Class 1 lasers are usually lasers in the visible region of the light spectrum. They are not considered hazardous. People are shielded from view of the laser light to prevent any exposure. There are no safety requirements needed for the use of class 1 lasers. Examples of class 1 devices include CD Players and certain laser printers.

Class 2 (II) Lasers:

Class 2 lasers can power up to 1 milliwatt (mW) and have a wavelength between 400 and 700 nm. These lasers are not optically dangerous to people because the eye reflex is able to react quick enough to prevent any damage. If class 2 lasers are exposed to the eye, the time frame that the eye is exposed is not long enough to be hazardous. This is due to the natural instinct to blink or turn away from the light. Examples of class 2 devices include certain laser pointers and barcode scanners.

Class 3a (IIIa) Lasers:

Class 3a lasers power between 1 mW and 5 mW. They can possibly be hazardous to the eye as they may produce spot blindness or other possible injuries. The amount of injury is still minimal after a short period of accidental exposure. Examples of class 3a devices include certain laser pointers and laser scanners.

Class 3b (IIIb) Lasers:

Class 3b lasers have an output power between 5 mW and 500 mW. This class of lasers is hazardous to the eye and can cause other injuries such as burning of the skin. Direct viewing, as well as beam reflections, can result in damage. Examples of class 3b laser uses include physiotherapy treatments and laser light shows.

Class 4 (IV) Lasers:

Class 4 lasers are high-powered devices with an output power greater than 500 mW. Direct laser beams and beam reflections are both hazardous to the eye as well as skin. If high output powers are used, class 4 lasers can also become a fire hazard. Examples of class 4 laser use are surgery, cutting metals, drilling, welding, and micromachining.

Please remember that high-output powered lasers create the greatest risk of injury. Keep reflective materials away to reduce the risk of reflection. Always wear protective goggles to keep your eyes from becoming damaged. Most importantly, be smart when using these highly dangerous lasers.