Daylight blasting rule inside a contained vessel

February 11, 1993

Mr. Kerry E. Saltzman
Fox and Grove
[Recipient address omitted]
Dear Mr. Saltzman:

This is in response to your November 17, letter requesting an interpretation of the Occupational Safety and Health Administration (OSHA) standards addressing the use of explosives (29 CFR 1926.900(j)). I apologize for the delay of this response.

With regard to whether the requirement to conduct blasting operations, insofar as possible, between sunup and sundown applies to blasting which is completely contained within a vessel, the answer is no. This requirement only addresses outdoor applications where daylight can help visually ensure that all personnel are removed or kept out of the blast hazard area.

Based on the information you provided concerning your process of removing refractory lining and iron residue, it appears that conducting blasting operations between 4:00 a.m. and 7:00 a.m. when employee exposure is at a minimum meets the intent of 1926.900(j).

Again, we apologize for the delay in our response and if we can be of any further assistance, please contact me or Mr. Dale R. Cavanaugh of my staff at (202) 219-8136.

Sincerely,
Roy F. Gurnham, Esq., P.E.
Director
Office of Construction and Maritime
Compliance Assistance

[Requester letter reproduced on OSHA page; omitted here.]