OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov.
May 28, 1992
MEMORANDUM FOR REGIONAL ADMINISTRATORS
ARA'S FOR TECHNICAL SUPPORT AREA DIRECTORS
Through: Thomas Shepich Leo Carey
From: David V. Loebach
Subject: Instruments Tested for Electromagnetic Susceptibility
A list of equipment we have tested for susceptibility to external electromagnetic fields is attached. Agency personnel can use this list as a guide to determine which instruments may be used with confidence in environments where electromagnetic radiation is present. If instruments are not designed for these environments, external electromagnetic fields can cause readings to be erroneous or the instruments to temporarily malfunction. A very common source of interference is communications equipment, such as walkie talkies. Some other sources are RF heat sealers, electric welders, and automotive ignition systems.
As the effects of electromagnetic susceptibility (EMS) become more widely known, challenges to citations based on EMS may arise. We are confident that we can support any citation challenged on the basis of EMS if we have tested the instrument and found it to meet the test criteria we have applied.
You or your staff should feel free to contact Ray Feldman at 513- 684-3721 if you would like technical assistance on EMS.
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