The Advanced Photon Source
a U.S. Department of Energy Office of Science User Facility

Experiment Hazard Class 10.1 – Microwaves and RF Generation


This hazard classification applies to working with or around radio frequency or microwave radiation (Non-Ionizing Radiation (NIR)).  At high levels and in certain conditions, NIR fields may pose hazards to personnel working in the area.  Other hazard classifications and associated controls may apply to experiments in this hazard class.

Experiment Category

Experiments involving previously reviewed hazard controls are categorized as medium risk experiments.

Experiments involving new equipment or modified hazard control schemes are categorized as high risk experiments.

Experiment Hazard Control Verification Statements

Engineered Controls – The establishment of applicable controls for the limitation of personnel exposure to NIR hazards.  The controls may include shielding, isolation, and work time limitations.

Procedural Controls – Consultation with NIR SME for recommendations on administrative and engineered controls as necessary.  Contact the local Floor Coordinator for assistance in scheduling a consultation.

Design Reviews and Equipment Inspections – A survey performed by a NIR SME on equipment that may produce a radio frequency/microwave (NIR) hazards.

Training – Equipment manufacturer's guidelines and/or NIR SME recommendations.

Signs and Labeling – Warning signs of the type specified in 29 CFR 1910.97 must be used to communicate NIR hazards.  Contact the Divisional ESH Coordinator for further information.

Personal Protective Equipment – None.

Monitoring – NIR extends from 30kHz to 300 GHz.

Exposure – NIR exposure must be limited to that allowed by the American Governmental Industrial Hygienists Threshould Limit Value.  A copy of this information is available from the Divisional ESH Coordinators.  Precautions to prevent electric shock must be taken where employees could exceed allowable continuous exposure limits.

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.


LMS-PROC-233, Radiofrequency and Microwave Fields 4/16/2020 (Internal link)

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

Reviewed: July 24, 2020