Advanced Photon Source

An Office of Science National User Facility

Experiment Hazard Class 9 – Electric and Magnetic Fields


This hazard classification applies to all experiments involving magnets, magnetic fields, and electric fields. Other hazard classifications such as electrical safety and their associated hazard controls may also apply to experiments in this hazard class.

Hazard Control Set

Controls – Persons with cardiac pacemakers or other medical devices that may be affected by magnetic or electric fields must be prohibited from entering areas where the steady state magnetic field exceeds 0.5 mT (5G) or the steady state electric field exceeds 1000 V/m. Barricades/warning tape as appropriate.

Procedural Controls – Safe work procedures to handle hazards should be developed. Shielding as feasible. Hand tools can become missiles in a sufficiently strong magnetic gradient, pinch hazards could be present; therfore limit personnel exposure. Only nonferromagnetic tools should be used in areas where the magnetic field may exceed 3 mT. Concerning Electric field strength greater than 5,000 V/m, eliminate ungrounded objects and/or use insulated gloves when ungrounded objects must be handled. Consult with ESQ-IH regarding safe work practices for work in electric fields that exceed 15,000 V/m

Design Reviews and Equipment Inspections – Medical Department must evaluate and counsel all employees with cardiac pacemakers or other medical implants

Signs and Labeling – Post areas where: Magnetic field exceeds 0.5 mt (5G), Electric field exceeds 1,000 V/M. Caution: DO NOT ENTER, Electromagnetic fields could be harmful to persons wearing pacemakers or other medical electronic implant. Signs are available through the APS ESH Coordinators

Personal Protective Equipment – Electric fields that exceed 15,000 V/m require the use of protective devices (suits, gloves, and insulation).

Hazard Control ASSISTANCE

Consultation is available through the APS ESH Coordinators and ESQ-IH. Please contact the local floor coordinators for arrangements.

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

Hazard Control Verification

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.


LMS-Proc-234:Electric and Magnetic 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