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Cornell observes the Threshold Limit Values (TLVs) published by the American Conference of Governmental Industrial Hygienists (ACGIH) as our guides for controlling exposures to magnetic fields, ultraviolet radiation, and radiofrequency radiation.

Magnetic Fields

This program applies to equipment that radiates static or time-varying magnetic fields. Examples include MRI (magnetic resonance imagining), SQUID (superconducting quantum interface device), NMR (nuclear magnetic resonance) spectrometers, particle accelerators, etc. If you are introducing new equipment to the lab that generates magnetic fields, please contact It may be necessary to map the safe boundary for medical implants like pacemakers, or take steps to prohibit magnetizable objects from the space to prevent them from becoming missiles in stronger fields.

Ultraviolet Radiation

The threshold limit value for daily exposures to occupational sources of UV radiation is 3 mJ/cm2. For example, a worker exposed to UV source emitting 3 mW/cm2 at the most hazardous UV wavelength of 270 nm would exceed the daily threshold in 1 second.

If your work involves an unenclosed source of UV radiation, please contact to request a consultation. EHS can provide a more in-depth hazard assessment and suggestions to support your work safely.

Radiofrequency Radiation

Radiofrequency (RF) radiation spans the frequency range from 30 kHz to 300 GHz. Microwave radiation is a subset of the RF range, spanning 300 MHz to 300 GHz.  Consumer electronics devices like cell phones and wireless routers conform with limits specified by the Federal Communication Commission and can be safely used without EHS consultation.

Please contact with questions about RF equipment. 

Written Program/Manuals

Magnet Safety Program Protected Document
RF and Microwave Safety Program Protected Document

Training Resources