Subpart J
Under 1926 Subpart J (Welding and Cutting), OSHA covers safety and health requirements for welding and cutting operations in construction. See the Welding and Cutting rules in 1926 Subpart J for the official standard references and scope.
Yes — under limited circumstances, LPG may be used underground only for welding, cutting, or other hot work. The OSHA Letter of Interpretation "LPG use in underground construction" (May 20, 1992) states that paragraph 1926.800(m)(5)(ii) specifically allows LPG underground use only for those purposes; see the LPG use in underground construction interpretation and review 1926 Subpart J (Welding and Cutting).
When using LPG underground for welding, cutting, or hot work, you must comply with the requirements in 1926 Subpart J plus the specific paragraphs referenced in the underground construction rule: paragraphs (j), (k), (m), and (n) of that section. The May 20, 1992 Letter of Interpretation explains that the risks are controlled by complying with those paragraphs; see the OSHA interpretation on LPG use in underground construction and 1926 Subpart J (Welding and Cutting).
The interpretation titled "LPG use in underground construction" was issued on May 20, 1992 by Patricia K. Clark, Director, Directorate of Compliance Programs. You can read that Letter of Interpretation at the OSHA site: LPG use in underground construction (May 20, 1992).
The welding and cutting regulations in 1926 Subpart J are issued under the authority of the Contract Work Hours and Safety Standards Act and the Occupational Safety and Health Act of 1970, among others. The Subpart J metadata lists these authorities; see 1926 Subpart J (Welding and Cutting) for the authority and regulatory context.
You can find the official regulatory text for welding and cutting in the OSHA webpage for 1926 Subpart J (Welding and Cutting). Access the standard text at 1926 Subpart J (Welding and Cutting).
OSHA considered comments requesting broader use of LPG underground but concluded the evidence was insufficient to change the proposal; instead OSHA limited LPG underground use to welding, cutting, or other hot work. The May 20, 1992 Letter of Interpretation summarizes this and references the preamble to the final rule; see LPG use in underground construction and 1926 Subpart J (Welding and Cutting).
OSHA states that risks from using fuel gases underground will be effectively controlled by complying with 1926 Subpart J and the specific paragraphs referenced in the underground construction section (j), (k), (m), and (n). The May 20, 1992 Letter of Interpretation advises relying on those regulatory controls; see the interpretation at LPG use in underground construction and the 1926 Subpart J (Welding and Cutting) standard.
For underground welding or cutting, review 1926 Subpart J and the underground construction provisions identified by OSHA—specifically paragraphs (j), (k), (m), and (n) of the applicable section—to ensure you meet the required controls. The May 20, 1992 Letter of Interpretation points to those requirements as the basis for safely using LPG underground; see LPG use in underground construction and 1926 Subpart J (Welding and Cutting).
Yes — OSHA’s final rulemaking record discussed allowing LPG underground for welding and related hot work in the preamble, and the May 20, 1992 Letter of Interpretation references that discussion (June 2, 1989 preamble, 54 FR 23824). See the LPG use in underground construction interpretation and 1926 Subpart J (Welding and Cutting).