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NOTICE: This is an OSHA Archive Document, and may no longer represent OSHA Policy. It is presented here as historical content, for research and review purposes only.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

August 21, 1978

Dean G. Kratz, Attorney
McGrath, North, O'Malley,
Kratz, Dwyer, O'Leary &
Martin, P.C.
300 Continental Building
Omaha, Nebraska 68102

Dear Mr. Kratz:

This is in response to your letter dated July 12, 1978, requesting a permanent variance from section 1910.309(a), Article 502-6(b) National Electrical Code, of the Occupational Safety and Health Standards. Your letter was forwarded to this office to determine if the standard applies in the situation described in your application.

29 CFR 1910.309(a) could be used as supporting material in a section 5(a)(1) violation of the Occupational Safety and Health Act of 1970 in circumstances where a locomotive with electrical switches, not properly enclosed, used in grain elevator loading or unloading areas that produce grain dust. However, it appears that if the administrative controls are implemented, as indicated in your variance application for the locomotive, a variance is unnecessary.

For information, I have enclosed a copy of a memorandum to our field staff dated May 19, 1978.

If I may be of any further assistance, please feel free to contact me.


John K. Barto, Chief
Division of Occupational
Safety Programming