Closed Beam & Low Classes Laser Safety (online) is recommended for users of class 1, 1M, 2, 2M and 3R open beam lasers and for the users of enclosed beam class 3B and class 4 lasers.
A laser system is considered enclosed if the user does not have access to laser radiation above maximum permissible exposure (MPE) during normal operation. This can be obtained through an enclosure and an interlock system. If the enclosure is opened during laser functioning, the interlock will shut down the class 3B or class 4 laser or activate a shutter to block the beam or to reduce the beam under the MPE.
If the enclosed beam system is open and the interlock defeated, the system becomes a class 3B or 4 system. The full laser safety training is mandatory to operate this system.