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 http://www.osha.gov.

May 20, 1992

MEMORANDUM FOR:     GABRIEL J. GILLOTTI
                   ASSISTANT REGIONAL ADMINISTRATOR
                   OFFICE OF TECHNICAL SUPPORT

FROM:               PATRICIA K. CLARK, DIRECTOR
                   DIRECTORATE OF COMPLIANCE PROGRAMS

SUBJECT:            Use of LPG Underground

Your January 30 memorandum to Roger A. Clark requesting an interpretation of underground construction regulations addressing the sue of liquified petroleum gas (LPG) has been referred to the Office of Construction and Maritime Compliance Assistance for response. I apologize for the delay in responding to you.

Paragraph 1926.800(m)(5)(ii) specifically allows the use of LPG underground only for purposes of welding, cutting or other hot work. This practice was proposed in the August 8, 1983, NPRM (48 FR 35774) and was discussed in the preamble to the final rule published on June 2, 1989 (54 FR 23824). In the final rulemaking, OSHA received comments similar to the professional tunnel engineer's comment mentioned in your memorandum and found "....the evidence insufficient to warrant changing the proposal. OSHA believes that the risks that may be associated with the use of fuel gases will continue to be effectively controlled by compliance with the paragraphs referred to in the rule; namely, 29 CFR Part 1926, Subpart J and paragraphs (j), (k), (m) and (n) of this section."