Archive Notice - OSHA Archive

NOTICE: This is an OSHA Archive Document, and may no longer represent OSHA Policy. It is presented here as historical content, for research and review purposes only.

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

February 9, 1993

Mr. David G. Sarvadi
Law Offices of Keller and Heckman
1001 G Street, N.W.
Suite 500
West Washington, D.C. 20001

Dear Mr. Sarvadi:

This is in response to your December 24, 1992 letter to Mr. Joseph Pipkin in the Directorate of Safety Standards Programs in the Occupational Safety and Health Administration (OSHA). Your letter, which was forwarded to this Directorate for response, requested OSHA documentation of interpretations of the 29 CFR 1910.303(a), that is approval requirements for electrical conductors and equipment with respect to involvement of a national recognized testing laboratory (NRTL). We apologize for the delay in responding.

Electrical "conductors" and "equipment" must be "approved", that is, "acceptable", as defined 29 CFR 1910.399 for the safeguarding of employees in the workplace. Please find enclosed OSHA policy and guidance documents, which are readily and publicly available, on NRTL accepted, certified, listed, labeled or otherwise- determined-to-be-safe electrical conductors and equipment used in the workplace.

Also enclosed is a current list of NRTL's which meet 29 CFR 1910.7 requirements. The kinds of electrical conductors and equipment which must be approved for use in the workplace can be determined more specifically through communication with the NRTL's.


Roger A. Clark,
Directorate of Compliance Programs