The Advanced Photon Source
a U.S. Department of Energy Office of Science 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 Safety Officer (Nena Moonier, 630-252-8504) for further assistance.  Other hazard classifications and their associated hazard controls may also apply to experiments in this hazard class.  For further information, 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 or a specular reflection of the 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.  Consultation is available from the ANL Laser Safety Officer. Consultation is available from the ANL-APS Deputy Laser Safety Officer.

Procedural Controls – No formal (written) procedure is required.  Laser use should conform to applicable parts of the American National Standards Institute for the Safe Use of Lasers, ANSI Z136.1 (2014).

Design Reviews and Equipment Inspections – None

Training – ANL recommends that experimenters who have not previously taken laser safety training take the laser safety course available at ANL.  However, laser safety training is not required for Class 2 lasers.  Notify your beamline host if you would like to take this 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 – None 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 having the authority to authorize experiments as listed in the ESAF system.  Approval by both the host beamline and APS Experiment Safety Review Board are mandatory prerequisites for experiment authorization.

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, 05/21/18 (Internal link)

Contact the APS User Safety Program with any questions or if the internal links are not working properly.

Reviewed: January 27, 2022