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.

December 4, 1995

Mr. Aldo M. Gonzalez
Health and Safety Manager
The Tyree Organization
208 Route 109
Farmingdale, N.Y. 11735

Dear Mr. Gonzalez:

This is in response to your letter of October 25 to the Occupational Safety and Health Administration (OSHA) in which you request an interpretation of 29 CFR 1926.352(c). Specifically, you asked what the standard means by the phrase "presence of other flammable compounds."

As you point out in your letter, although the subject standard does not specify a minimum separation distance between flammable compounds and sources of ignition, other OSHA standards related to fire protection require a minimum separation distance of 20 to 25 feet. We have reviewed those standards and believe that the appropriate minimum separation distance for application of Section 1926.352(c) is also 20 feet (measured horizontally). However, this distance may be insufficient if the source of ignition is at a lower elevation than a heavier-than-air flammable compound and vapors can flow to the ignition source.

If you require further assistance, please do not hesitate to contact either myself or Mr. Dale Cavanaugh of my staff at (202) 219-8136.

Sincerely,

Roy F. Gurnham, P.E., J.D.
Director
Office of Construction and Maritime
Compliance Assistance