Most of the letters of interpretation issued by OSHA over the years have dealt with PSM applicability issues. However, this newsletter will focus on several interpretations dealing with hot work permits. This regulation governing hot work permits is considered part of the PSM Standard by reference. Paragraph (k) of 29 CFR 1910.119, the PSM hot work permit element, refers to 29 CFR 1910.252(a), the welding and brazing fire protection standard. Note that many of these interpretations pre-date the adoption of the final PSM Standard.
Interpretations of PSM Standard With Respect to Hot Work Permits
Question: What is the definition of hot work?
Answer: Hot work is any spark producing operation, including welding, brazing, grinding, burning, etc. [OSHA Instruction CPL 2-2.45A CH-1, Compliance Directive for PSM Standard]
Question: What are the separation requirements for acetylene (welding gas) and oxygen bottles?
Answer: 29 CFR 1910.252(a)(2)(iii) requires a 20 ft. separation when oxygen and acetylene bottles are in storage. However, the separation required also depends on whether or not the conditions constitute "storage" of these bottles within the meaning of this particular standard. The generally accepted meaning of the word "storage" contemplates removal of an object from regular use for an appreciable period of time. Placing an object aside for a short period of time with the intent of using it again, would in our opinion not constitute storage of the object. Therefore, the 20 ft. separation requirement would not apply. [OSHA internal memo of 9/5/90]
Question: What is the policy for maintaining sprinkler systems?
Answer: 1910.252(a)(2)(vi)(B) prohibits the performance of welding and cutting in an area equipped with an inoperable sprinkler system. Therefore, the standard implies that welding and cutting should be performed in areas with properly functioning sprinkler systems. The lack of an operable sprinkler system would constitute a violation. On the other hand, if an operation did not require the presence of a properly functioning sprinkler system according to a particular standard, the existence of an impaired sprinkler system would not constitute a violation. [OSHA internal memo of 1/14/99]
Question: Does the introduction of electrical welding equipment automatically make a confined space a Permit-Required Confined Spaces (PRCS) in accordance with standard 29 CFR 1910.146?
Answer: As long as the protective measures of Subpart Q - Welding, Cutting and Brazing, prevent a hazard from developing, the use of electrical welding equipment would not cause a confined space to be classified as PRCS. The protective measures of other standards would be applicable to the work in this space, specifically the following paragraphs of Subpart Q. [1910.252(a)(4)(i), 1910.252(b)(4)(i) to (vii), 1910.252(c)(4), 1910.252(c)(9), and 1910.252(c)(10)] must be followed. [OSHA letter of 5/12/97]
Question: Are tips part of a welding torch or a separate item?
Answer: The welding, cutting and brazing standards as written are interpreted to include tips as a part of the complete assembly of the torch and as such cannot be considered a separate item. We do not interpret 1910.252(a)(1)(iii) to exclude replacement tips when such tips are made to the same specifications as the original tip of the torch at the time of approval by the nationally recognized testing laboratory. [OSHA letter of 9/2/77]
Although verbal interpretations have no official standing and federal employees rarely speak for attribution, there have been a number forums following the adoption of the PSM Standard where OSHA representatives have made themselves available to speak about PSM and to answer questions. These verbal interpretations contain some interesting information on OSHA’s thinking (or at least the thinking of the person answering the question). Also, OSHA has published non-mandatory guidance on PSM issues in OSHA Publication 3133 (the “purple booklet”). This guidance is also unofficial and is not mandatory. The following clarification published in OSHA 3133 is pertinent to hot work permits:
The hot work procedure must have a step where clearance is granted to start the job.
To see a specific letter or other interpretive document published by OSHA, visit OSHA’s website at
As a service to our clients and readers, AcuTech has included many of these documents, including the letters of interpretation discussed above, in a continuous Word® file. This file allows for easier searching for keywords that might be of interest and makes it easier to determine if an interpretative document has been published on a particular topic or if any of them address a specific PSM-related issue.
Note to our readers who have downloaded or used the interpretations file in the past: This file has been updated and now includes interpretations from the OSHA regulations that form the requirements for an emergency response plan, including alarm system and HAZWOPER training requirements. The updated file may be found at
In the next month’s issue of the AcuSafe newsletter, we will include additional discussions of interpretations related to
Hot Work Permitting.
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