Key Controls, Warning Systems, Beam Pathways

Control measures address key controls, warning systems, and beam pathways.

Key Controls

All Class 4 lasers and laser systems require a master switch control, operated by a key or computer code. When disabled, the laser is not operational. Only authorized system operators can access the key or code. Including a master switch control on Class 3B lasers and laser systems is also recommended but not required.

Warning Systems

An audible tone or bell, or a visual warning, is recommended as an area control for Class 3B laser operation. Such a warning system is mandatory for Class 4 lasers. These warning devices should activate upon system start-up and should have a sound distinct to the laser operation. Verbal countdown commands are an acceptable audible warning and should be a part of the SOP.

Beam Pathways

Class 4 lasers require a permanently attached beam stop or attenuator, which can reduce the output emission to a level at or below the appropriate MPE level when the laser system is on standby. Such a beam stop or attenuator is also recommended for Class 3A and Class 3B lasers.

If a high-powered laser's path has been totally embedded within a protective enclosure that is properly labeled and properly safeguarded with protective housing interlocks, then it is considered to have the hazards of a Class 1 laser and may be operated in the enclosed manner with no additional controls for the operator.

To learn more about Laser Safety visit our Laser Safety Online Training web page.