- Standard Number:1910.309(c)1926.400(h)
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.
April 22, 1977
Mr. Larry Payne
L & B Tool Repair
3439 W. 70th Street
Shreveport, Louisiana 71108
Dear Mr. Payne:
Your interest in the Occupational Safety and Health Standards is appreciated.
In reference to your request of April 15, 1977, concerning the approval for assembly of GFCIs under 29 CFR 1910.309(c) and 29 CFR 1926.400(h), I submit the following.
The conductors and equipment required or permitted by the National Electric Code (NEC), NFPA 70-1971 must be accepted, or certified, or listed or labeled, or otherwise determined to be safe by a nationally recognized testing laboratory. There are two nationally recognized testing laboratories acceptable to the Assistant Secretary of Labor. These are Underwriters' Laboratories, Inc., and Factory Mutual Research Corporation.
The National Electrical Manufacturers Association (NEMA) is not a testing laboratory. It is an association which, among other things, produces product manufacturing standards. Some of these standards may be used by the testing laboratory.
In checking with our National Office in Washington, D. C., it was their opinion that, even though components in the GFCI were U.L. accepted, the completed assembly or product must be evaluated by an accredited testing laboratory, as aforementioned, in meeting the requirements for approval.
If I may be of further assistance please let me know.
Sincerely yours,
C. R. Holder
Assistant Regional Administrator
for Technical Support