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.

April 22, 1985

Joseph F. Drayton, Director
New York State Department of Labor
Division of Safety and Health
Two World Trade Center
New York, New York 10047

Dear Mr. Drayton:

This is in response to your letter of December 27, 1984, addressed to New York Regional Administrator Gerald P. Reidy, in which you raised a concern over a conflict between Occupational Safety and Health Administration (OSHA) standards 29 CFR 1910.156(f)(1)(i), 1910.156(f)(1)(iii), and a notice issued by the National Institute for Occupational Safety and Health (NIOSH).

There is no true conflict in these standards because 1910.[156](f)(1)(iii) is more specifically applicable to the use of a "buddy breathing" device or quick disconnect valve by fire brigade members than is 1910.156(f)(1)(i). Pursuant to 29 CFR 1910.5(c), the more general provision is pre-empted by the more specific.

It must be emphasized that not all "buddy-breathing" devices will be permitted as accessories under 29 CFR 1910.156(f)(1)(iii). These accessories are not permitted if they cause damage to the breathing apparatus, restrict the air flow of the breathing apparatus, or obstruct the normal operation of the breathing apparatus. It should also be emphasized that OSHA does not mandate that a SCBA be equipped with these accessories, and OSHA's allowance for the use of these accessories pertains only to SCBA's worn by fire brigade members, and then only for emergency situation purposes. See Appendix A, 1910.156, paragraph 8, copy enclosed.

Under 29 CFR 1910.156(f)(1)(i), when a self-contained breathing apparatus (SCBA) is provided by the employer for use by fire brigade members, it must be certified by NIOSH under [42 CFR Part 84]. NIOSH certifies only complete respirator assemblies, not individual parts or accessories. The SCBA with the parts or accessories attached can be tested to attest to the fact that the parts or accessories do not affect the performance of the SCBA in its normal, one-person-use mode of operation.

While NIOSH will certify a SCBA with accessories, it will not certify that the accessory such as the "buddy-breathing" device can be safely used. Nevertheless, OSHA in section 1910.156(f)(1)(iii) allows the use of these devices, if they do not adversely affect the SCBA. Additionally, if a SCBA is field modified by addition of one or both of these accessories, its NIOSH certification will be voided. However, use of such a device does not necessarily constitute an OSHA violation if the criteria in 1910.156(f)(1)(iii) are met. Although at this time OSHA is not aware of any field modification device that meets the criteria established for these devices in the standard, it is important to note that since promulgation of the fire brigade standard, most major manufacturers of SCBA now have their SCBA's with these accessories NIOSH-certified. Some of these companies include the following:

Survivair Division of U.S. Divers Corporation
3323 W. Warner Avenue
Santa Ana, California 92702

Clifton Precision
Post Office Box 303
Frederick, Delaware 19946

Scott Aviation
225 Erie Street
Lancaster, New York 14086

Globe Safety Products
125 Sunrise Place
Dayton, Ohio 45407

National Draeger, Inc.
401 Parkway View Drive
Pittsburgh, Pennsylvania 15205

[This document was edited on 11/24/98 to strike information that no longer reflects current OSHA policy.]

NIOSH has received questions and complaints in regard to unapproved field modifications to MSHA/NIOSH certified respirators. Some problems reported to NIOSH have, upon investigation, been found to have been caused by the users modifying certified respirators, resulting in the modified respirator failing to perform as anticipated, thus jeopardizing the respirator user. A user who field-modifies a certified respirator may not be able to determine whether a change will decrease respiratory protection and may be in violation of 1910.156.

If you have any further questions, please contact us.


John B. Miles, Jr., Director
Directorate of Field Operations