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Standard Interpretations - Table of Contents
• Standard Number: 1910.134(b); 1910.134(g)(4); 1910.155(c)(26); 1910.156(a)(2)

July 8, 2002

Mr. Robert Weilding
23115 McGuire Road
Wilmington, Illinois 60481

Dear Mr Weilding:

Thank you for your April 3 letter to the Occupational Safety and Health Administration (OSHA) regarding fire brigades and the use of respirators. This letter constitutes OSHA's interpretation only of the requirements discussed and may not be applicable to any question not delineated within your original correspondence. Your questions are restated below, followed by our replies.

Question: If there is visible smoke present during a structure/building fire, would responders be required to wear SCBA units within the contaminated atmosphere as stated in 29 CFR 1910.134(g)(4)?

Reply: The presence of visible smoke itself does not trigger a requirement to wear any particular type of respirator. Fires that have not progressed beyond the incipient stage, such as stove grease fires, might be extinguished without the responders needing to wear any respiratory protection. Larger fires, which have progressed beyond the incipient stage, would require SCBAs for entry.

Question: If responders are required to wear SCBAs, would this be considered beyond the incipient stage fire as defined in 29 CFR 1910.155?

Reply: An incipient stage fire is defined as a fire that is in the initial or beginning stage and can be controlled or extinguished by portable fire extinguishers, Class II standpipe, or small hose systems without the need for protective clothing or breathing apparatus. Wearing more protective equipment than necessary for that fire, such as an SCBA, would not upgrade the class of fire.

Question: If responders are required to extinguish fires and/or rescue people, and there is visible smoke and the responders are wearing SCBAs, is this considered interior structural fire fighting as stated in 1910.134(b)?

Reply: As stated above, neither the presence of smoke nor the wearing of personal protective equipment (PPE) changes the class of a fire. The nature of the fire determines whether PPE should be used.

Question: If responders are wearing SCBAs in fire-contaminated atmospheres to extinguish a fire or rescue someone during interior structural fire fighting, would employers be required to comply with 29 CFR 1910.156?

Reply: The fire brigade standard, 1910.156, applies to all fire brigades except airport crash rescue and forest fire fighting operations. The personal protective equipment requirements apply only to members performing interior structural fire fighting.

Thank you for your interest in occupational safety and health. We hope you find this information helpful. 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 If you have any further questions, please feel free to contact the [Office of General Industry Enforcement] at (202) 693-1850.


Richard E. Fairfax, Director
[Directorate of Enforcement Programs]

Standard Interpretations - Table of Contents

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