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 http://www.osha.gov.

January 17, 2017


Mr. Richard F. Graham, Jr.
116 Broadwater
Williamsburg, Virginia 23188

Dear Mr. Graham,

Thank you for your letter to the Occupational Safety and Health Administration (OSHA). Your letter was referred to OSHA's Directorate of Enforcement Programs for a response to your question. In your letter, you asked about OSHA's Respiratory Protection standard, 29 CFR 1910.134, and the requirements for respirator fit testing with and without respirator facepiece accessories. You were also called by a member of my staff to clarify your question. 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 specific question and our response are below.

Background: You mentioned that accessories like thermal imaging cameras and electronic voice amplifiers can be attached to the facepiece of a self-contained breathing apparatus (SCBA) used in firefighting.  The cameras weigh approximately ½ pound.  

Question 1: Does a person who wears a thermal imaging camera that mounts onto the facepiece of a respirator need to be fit tested both with and without the accessory?

Response: Yes.  The OSHA Respiratory Protection standard (29 CFR 1910.134) requires employees to be fit tested prior to the initial use of a respirator, and whenever a different respirator facepiece (i.e., of a different size, style, model or make) is used (see 29 CFR 1910.134(f)(2)). Additionally, Appendix A to OSHA's Respiratory Protection standard provides information on mandatory fit testing procedures when wearing safety equipment with a respirator. The general requirements for fit-testing procedures are listed within Appendix A, Part I (OSHA-Accepted Fit Test Protocols). Item 13 on the list states:

The fit test shall be performed while the test subject is wearing any applicable safety equipment that may be worn during actual respirator use which could interfere with respirator fit.

Accordingly, if a respirator facepiece would also be used with an attached accessory, such as a camera or voice amplifier, then fit testing must be performed twice; i.e., both with and without the accessory attached to the facepiece. This is because the placement and the weight of the accessory could affect the facepiece fit, especially during movement of the head and face.

One further consideration is that OSHA's Respiratory Protection standard (at 29 CFR 1910.134 (d)(1)(ii)) requires that respirators used to protect workers must be certified by the National Institute for Occupational Safety and Health (NIOSH). NIOSH certification applies only to the manufacturer's specified respirator configuration, as tested by NIOSH.  Any after-market or user modification to a certified respirator configuration may affect the integrity of the respirator and the protection it provides.  To ensure compliance with the NIOSH-approval requirement of the OSHA standard, any configuration of an accessory with a respirator facepiece must be tested and certified by NIOSH before it can be used. OSHA is aware that NIOSH has recently certified some configurations of respirator facepieces with the types of accessories that you mention.

Thus, when firefighters use multiple NIOSH-certified configurations (e.g., facepiece with or without accessories attached), then fit testing must first be performed for each and every NIOSH-certified configuration.

Thank you for your interest in occupational safety and health. We hope you find this information helpful. OSHA's requirements are set by statute, standards, and regulations. Our letters of interpretation do not create new or additional requirements but rather explain these requirements and how they apply to particular circumstances. This letter constitutes OSHA's interpretation of the requirements discussed. From time to time, letters are affected when the Agency updates a standard, a legal decision impacts a standard, or changes in technology affect the interpretation. To assure that you are using the correct information and guidance, please consult OSHA's website at www.osha.gov. If you have any further questions, please feel free to contact the Office of Health Enforcement at (202) 693-2190.



Thomas Galassi, Director 
Directorate of Enforcement Programs