Advanced Photon Source

An Office of Science National User Facility

Experiment Hazard Class 4.2 – Use of Class 2 Lasers


This hazard classification applies to all experiments involving class 2 lasers that do not require staring into the laser beam or a specular reflection of the beam. If an experiment will require personnel to stare into the beam of a class 2 laser, it is not covered by hazard class 4.2 and the experimenters should contact the APS User Experiment Safety Coordinator. Other hazard classifications and their associated hazard controls may also apply to experiments in this hazard class. See the summary of laser operation requirements.

Class 2 laser output cannot exceed 1x10-3 watts (1 miliwatt) total power.

Experiment Category

All Hazard Class 4.2 experiments that do not require staring into the laser beam are low risk experiments.

Experiment Hazard Control Verification Statements

Engineered Controls – None

Administrative Controls – Secure work area to prevent unexpected exposure to class 2 laser devices such as alignment tools.

Procedural Controls – No formal (written) procedure is required. Laser use should conform to applicable parts of the American National Standard for the Safe use of Lasers, ANSI Z136.1 (2000), The Safe Use of Lasers.

Design Reviews and Equipment Inspections – None


ANL recommends that experimenters who have not previously taken laser safety training take the laser safety course available at ANL. Laser safety training is not required for class 2 lasers. Notify your host Beamline Manager if you would like to take training.
Signs and Labeling – The area where the laser is used (e.g. experiment station) shall be posted as required by the Argonne Laser Safety Officer.

Personal Protective Equipment – Not required.

Experiment Authorization

Unless otherwise noted in the approved experiment safety plan, the PSC Deputy Associate Laboratory Director of Operations delegates the authority to authorize an experiment in this hazard class to a member of the APS Experiment Safety Review Board and resident beamline personnel appearing in the PSC Deputy Associate Laboratory Director's list of personnel having the authority to authorize experiments.

Hazard Control Verification

The PSC Deputy Associate Laboratory Director of Operations delegates responsibility for verifying that required controls are in place to the experiment On-site Spokesperson and Beamline Management.


ANL LMS PROC-285 Laser Safety, 12/18/13. (Internal link)

Please contact Bruce Glagola or Nena Moonier if you can not access the internal link

Reviewed March 14, 2017