Advanced Photon Source

An Office of Science National User Facility

Experiment Hazard Class 10.1 – Microwaves and RF Generation


This hazard classification applies to working with or around radiofrequency or microwave radiation (RFMW).At high levels and in certain conditions RFMW 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 qualify for categorized as medium risk.

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

Experiment Hazard Control Verification Statements

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

Procedural Controls – Consultation with ESQ Industrial Hygiene for recommendations on administrative and engineered controls as necessary. Arrangements for consultation may be made by the floor coordinators or the APS ESH Coordinators.

Design Reviews and Equipment Inspections – A survey performed by an Industrial Hygienist on equipment that may produce a radiofrequency/microwave hazards.

Training – Equipment manufacturer's guidelines, ESQ-IH recommendations

Signs and Labeling – Warning signs of the type specified in 29CFR 1910.97 must be used to communicate RFMW hazards, contact APS  ESH Coordinators

Personal Protective Equipment – Not readily available and not a plausible option

Monitoring – RFMW extends from 30kHz to 300 GHz

Exposure – RFMW exposure must be limited to that allowed by the American Governmental Industrial Hygienists Threshould Limit Value. Copies are available from the division safety coordinators. Precautions to prevent electric shock must be taken where employees could be exceeding allowable continuous exposure limits.

Experiment Authorization

The PSC Deputy Associate Laboratory Director of Operations delegates responsibility for verifying that required controls are in place to personnel delegated the authority to perform this task to the experiment On-site Spokesperson, and Beamline Management personnel having experiment safety responsibilities.

Hazard Control Verification

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 Review Board and any of the persons in the beamline personnel that appear in the list of Beamline Manager personnel authorized to approve experiments.


LMS-PROC-233, Radiofrequency and Microwave Fields , 5/9/2016 (Internal link)

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

Reviewed: March 10, 2017