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.

January 8, 1992

Mr. Victor Mondello
Norfolk Electric
19 Bradston Street
Boston, Massachusetts 02118

Dear Mr. Mondello:

This is in response to your November 6 letter requesting Occupational Safety and Health Administration (OSHA) concurrence or comment on the equipment you intend to use to furnish temporary power for a construction site.

In regard to whether the equipment listed in your letter is in compliance with OSHA rules please be advised that all electrical conductors and equipment must be approved (29 CFR 1926.403(a)). The definitions of "approved" and "acceptable" in 29 CFR 1926.449 indicate that the Agency will accept equipment that has been determined to be safe by a qualified electrical testing laboratory (i.e., a Nationally Recognized Testing Laboratory or NRTL). The Electrical Testing Laboratory of the City of Los Angeles is not currently recognized by OSHA. A list of NRTL's is enclosed for your information.

If we can be of any further assistance, please contact Mr. Roy Gurnham or Dale Cavanaugh of my staff in the Office of Construction and Maritime Compliance Assistance at (202) 523-8136.


Patricia K. Clark, Director
Directorate of Compliance Programs