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 02, 1981

Mr. Allan Staib
Engineering Services
General Foods Corporation
Maxwell House Division
P.O. Box 248
Houston, Texas 77001

Dear Mr. Staib:

This is in response to your letter of October 19, 1981, requesting a clarification of the Subpart L standards.

29 CFR 1910.155(c)(26) defines "incipient stage fire" as a fire which is in the initial or beginning stage and which can controlled or extinguished by portable fire extinguishers, class II standpipe or small hose systems without the need for protective clothing or breathing apparatus.

29 CFR 1910.155(c)(28) defines "interior structural fire fighting" as the physical activity of fire suppression, rescue or both, inside of buildings or enclosed structures which are involved in a fire situation beyond the incipient stage.

If your employees must wear breathing apparatus as you state in your letter because the smoke generated by a smolding fire is of such large quantity, then that fire can not be considered "incipient". "Incipient" infers a fire that has just begun and is of such size that poor visibility, smoke inhalation, and high temperatures have not reached the degree to require the use of breathing apparatus. We believe interior structural fires are fires of the type where it is necessary to wear breathing apparatus in order to be adequately protected.

I hope that the above information has clarified any questions you may have had with the standard.

If I may be of further assistance, please call or write.


Patrick R. Tyson
Acting Director,
Federal Compliance and State Programs