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NOTICE: This is an OSHA Archive Document, and may no longer represent OSHA Policy. It is presented here as historical content, for research and review purposes only.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

May 22, 1975

Mr. A. F. Robb
Metal-Cladding, Inc.
470 Niagra Parkway
North Tonawanda, N.Y. 14120

Dear Mr. Robb,

This is in response to your letter requesting clarification of OSHA standard 1910.107(c)(6) on location of electrical motors in a spray operation.

The OSHA standard requires compliance with Subparts 1910.309 which references the National Electric Code NFPA 70 1971. NFPA 70 on page 298, paragraph 500-4 sets forth requirements for use of electrical motors in atmospheres containing fumes of flammable substances, Class 1 Division 2. Class and division are described in NFPA 70 on page 290. In substance if the electrical motor fails to meet the requirements of spark or static proof it must be isolated from the spray room (not mounted on the spray room wall) at least 20 feet distant or it must meet all requirements for non-sparking motors.

Please feel free to contact us if there are further questions on OSHA.


Alfred Barden
Assistant Regional Director
Occupational Safety and Health