Standard Interpretations
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. Each 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.
- 1910.134 - Acceptance of closed-circuit self-contained breathing apparatus for firefighting. - 03/24/1987
- 1910.134 - Additional duties of two standby personnel for structural firefighting - 02/29/2012
- 1910.134 - Additional Enforcement Policy Change for Respiratory Protection Required for Abrasive Blasting. - 03/31/1997
- 1910.134 - APF for the combination pressure-demand, full-facepiece SAR with auxiliary SCBA - 11/04/2013
- 1910.134 - Applicability of OSHA's definition of oxygen-deficient atmosphere to Air Force facilities - 07/16/2024
- 1910.134 - Application of the Hazard Communication standard to gray and ductile iron castings. - 11/19/1985
- 1910.134 - Beards may not interfere with face seal;alternative respirators for bearded employees. - 03/07/2003
- 1910.134 - Belt mounted filtration unit used with any NIOSH approved supplied-air respirator. - 09/04/1996
- 1910.134 - Carbon Monoxide Alarm/Monitoring at Abrasive Blasting Operations. - 01/24/1980
- 1910.134 - Clarification on equivalent test nebulizer for qualitative fit tests. - 11/13/2009
- 1910.134 - Clarifications for breathing air quality and use - 05/31/2023
- 1910.134 - Conditions where OSHA might accept a product that is not approved by NIOSH. - 10/22/1997
- 1910.134 - Conduct of respiratory protection medical evaluations by medical technicians. - 10/16/1998
- 1910.134 - Definition of a single use and negative pressure respirator - 01/29/2010
- 1910.134 - Difference between voluntary and non-voluntary use of a respirator. - 07/14/2009
- 1910.134 - Employee declination of medical evaluation; religious exemptions for respirator use. - 12/02/1998
- 1910.134 - Escape-only respirators - 09/04/2019
- 1910.134 - Facial hair and respirator wearing. - 03/29/1985
- 1910.134 - Facial hair and the wearing of respirators. - 02/21/1985
- 1910.134 - Facial hair and voluntary use of filtering facepiece respirators. - 02/06/2006
- 1910.134 - Facial Hair Under Seal of Tight-fitting Respirator - 09/14/2012
- 1910.134 - Fit testing and fit factors for the N-95 respirators for protection against TB exposure. - 03/04/1996
- 1910.134 - Fit testing for CBRN respirators. - 10/26/2011
- 1910.134 - Fit testing requirements for respirators used for CBRN protection. - 12/27/2011
- 1910.134 - Hazwoper training in hospitals. - 12/02/1991
- 1910.134 - Incipient stage fire brigades. - 07/18/1996
- 1910.134 - Inquiry on beards, respirator use, and fit testing of repirators. - 10/03/1996
- 1910.134 - Interpretation of the Personal Protective Equipment standard - 07/03/1995
- 1910.134 - Job requiring respiratory protection. - 04/16/1996
- 1910.134 - Numerous questions on filtering facepiece/dusk mask respirators. - 11/22/2011
- 1910.134 - OSHA tuberculosis (TB) enforcement. - 04/06/1995
- 1910.134 - OSHA's decision not to provide a religious exemption from the respirator standard. - 08/05/2011
- 1910.134 - Particulate Respirators Certified under 42 CFR Part 84. - 09/03/1996
- 1910.134 - Permissible Exposure Limits for Nuisance dust. - 05/15/1997
- 1910.134 - Permit-Required Confined Space Entry Requirements For IDLH and Non-IDLH Spaces - 07/17/2014
- 1910.134 - Preemption of respiratory protection standard by DOT's Office of Pipeline Safety regulations. - 04/08/1999
- 1910.134 - Protection factors for respirators used in pharmaceutical industry: policy change. - 05/30/2002
- 1910.134 - PSM compliance for ammonia refrigeration systems. - 07/12/2006
- 1910.134 - Pulmonary function testing training requirements and spirometer transmission of disease. - 06/17/1993
- 1910.134 - QLFT fit testing procedures - 03/18/2015
- 1910.134 - Questions and answers regarding the respiratory protection standard - 10/16/1998
- 1910.134 - Requirements for fit testing employees before fire brigade training exercises. - 10/18/2004
- 1910.134 - Respirator Exhalation Valve Leakage. - 05/25/1994
- 1910.134 - Respirator rules as applied to open hatch gauging of sour crude oil storage tanks. - 06/11/1990
- 1910.134 - Respiratory protection against COVID-19 for employees with religiously mandated facial hair - 12/16/2021
- 1910.134 - Respiratory protection and emergency escape requirements for IDLH atmospheres. - 01/13/2003
- 1910.134 - Respiratory protection as it relates to oil fields - 04/14/1993
- 1910.134 - Respiratory protection compliance responsibility for contract workers and visitors. - 09/15/1987
- 1910.134 - Respiratory protection for anhydrous ammonia storage installations. - 12/07/1998
- 1910.134 - Respiratory Protection for Mercury and Chlorine - 03/01/1989
- 1910.134 - Respiratory protection requirements for sour crude oil tank operations. - 04/25/1989
- 1910.134 - Respiratory protection, medical surveillance, and training requirements under HAZWOPER - 09/24/2002
- 1910.134 - Sampling Procedures for Employees Using Air-Supplied Respirators - 06/27/1989
- 1910.134 - South Carolina's regulatory procedures for single-use respirators. - 09/01/1992
- 1910.134 - Spray painting relating to vehicle maintenance operations. - 07/28/1992
- 1910.134 - Storage of flammable and/or combustible liquids. - 02/23/1994
- 1910.134 - The M-17 gas mask may not be used by workers other than enlisted military personnel. - 04/21/1986
- 1910.134 - The Use of the Bullard "Free Air" Pump. - 04/18/1996
- 1910.134 - Training and PPE requirements for hospital staff that decontaminate victims/patients. - 12/02/2002
- 1910.134 - Training required for emergency response at industrial facilities - 06/04/1991
- 1910.134 - Training requirements of Hazwoper for various functions. - 08/20/1991
- 1910.134 - Tuberculosis: respiratory protection and complaint inspection. - 04/22/1996
- 1910.134 - Use of Air-Purifying Respirators In Dangerous Concentrations of Gases Or Vapors - 01/10/1990
- 1910.134 - Use of Bureau of Mines Approved Gas Mask Canisters - 11/15/1985
- 1910.134 - Use of eyeglass inserts or spectacle kits inside respirator full facepieces. - 04/07/1987
- 1910.134 - Use of smoke escape hoods meeting the ANSI-ISEA standard - 08/11/2010
- 1910.134 - Variance exposure level for silver metal. - 05/15/1996
- 1910.134 - Ventilation for an anhydrous ammonia refrigeration system. - 06/13/1990
- 1910.134 - Voluntary safety and health audits under the Occupational Safety and Health Act - 09/11/1996
- 1910.134 - Voluntary use of surgical masks - 12/20/2017
- 1910.134 - Voluntary use respirators - 04/26/2018
- 1910.134(a) - Facial hair and voluntary use of filtering facepiece respirators. - 02/06/2006
- 1910.134(a)(1) - Respirators for silica dust must be selected based on exposure levels. - 05/12/1999
- 1910.134(a)(2) - Paragraph (a)(2) applies to respirators provided for emergency use. - 12/22/1983
- 1910.134(a)(2) - Respirators for silica dust must be selected based on exposure levels. - 05/12/1999
- 1910.134(b) - Classification of fires; respiratory protection to extinguish fires. - 07/08/2002
- 1910.134(b) - Filtering facepiece respirators and medical evaluations - 04/24/2018
- 1910.134(b) - Numerous questions on filtering facepiece/dusk mask respirators. - 11/22/2011
- 1910.134(b) - OSHA's decision not to provide a religious exemption from the respirator standard. - 08/05/2011
- 1910.134(c) - Medical evaluation requirements under the respiratory protection standard - 10/05/1998
- 1910.134(c) - Respiratory protection requirements for hospital staff decontaminating chemically contaminated patients. - 09/05/2002
- 1910.134(c) - Training and PPE requirements for hospital staff that decontaminate victims/patients. - 12/02/2002
- 1910.134(c) - Use of Air-Purifying Respirators In Dangerous Concentrations of Gases Or Vapors - 01/10/1990
- 1910.134(c)(1) - Escape-only respirators - 09/04/2019
- 1910.134(c)(1)(ii) - Pulmonary function testing training requirements and spirometer transmission of disease. - 06/17/1993
- 1910.134(c)(2) - Filtering facepiece respirators and medical evaluations - 04/24/2018
- 1910.134(c)(2) - Numerous questions on filtering facepiece/dusk mask respirators. - 11/22/2011
- 1910.134(c)(2) - Respirators for voluntary use and cleaning respirators during fit testing. - 10/01/1999
- 1910.134(c)(2) - Use of smoke escape hoods meeting the ANSI-ISEA standard - 08/11/2010
- 1910.134(c)(2) - Voluntary use respirators - 04/26/2018
- 1910.134(c)(2)(ii) - Facial hair and voluntary use of filtering facepiece respirators. - 02/06/2006
- 1910.134(c)(4) - Clarification of respirator costs, annual training, and "effective" seal checks. - 12/23/1998
- 1910.134(c)(4) - Voluntary use respirators - 04/26/2018
- 1910.134(d) - Assessing hazards to select eye and respiratory protection. - 11/11/1998
- 1910.134(d) - Hooded versus tight-fitting respirators when complying with the Asbestos Standard - 07/18/2017
- 1910.134(d) - Qualitative and quantitative fit tests versus assigned protection factors - 05/23/2017
- 1910.134(d) - The OSHA interpretation of respiratory protection requirements with regards to tuberculosis (TB) exposure. - 02/05/1996
- 1910.134(d) - The relationship between OSHA standards and the usage of particulate respirators. - 03/18/1996
- 1910.134(d) - Use of Air-Purifying Respirators In Dangerous Concentrations of Gases Or Vapors - 01/10/1990
- 1910.134(d)(1) - OSHA's decision not to provide a religious exemption from the respirator standard. - 08/05/2011
- 1910.134(d)(1) - Respiratory protection against COVID-19 for employees with religiously mandated facial hair - 12/16/2021
- 1910.134(d)(1)(i) - Beards may not interfere with face seal;alternative respirators for bearded employees. - 03/07/2003
- 1910.134(d)(1)(i) - Selection of air purifying respirators for gases and vapors with poor warning properties (diisocyanates) - 07/18/2000
- 1910.134(d)(1)(ii) - Clarifications for breathing air quality and use - 05/31/2023
- 1910.134(d)(1)(ii) - NIOSH approved respirator during the period of an employee's escape from a chemical release of phosgene. - 07/01/1997
- 1910.134(d)(1)(ii) - OSHA requirements for respirator fit testing with and without facepiece accessories - 01/17/2017
- 1910.134(d)(1)(ii) - Respirators for voluntary use and cleaning respirators during fit testing. - 10/01/1999
- 1910.134(d)(1)(ii) - SCBA cylinder interchangeability. - 06/20/1997
- 1910.134(d)(1)(ii) - Use of non-approved respirators and improper use of approved respirators - 01/24/1991
- 1910.134(d)(1)(ii) - Using combinations of respiratory protection not approved by NIOSH. - 01/29/1999
- 1910.134(d)(2)(i)(A) - Clarification of OSHA's requirement for breathing air to have at least 19.5 percent oxygen content. - 04/02/2007
- 1910.134(d)(2)(i)(B) - Clarification of OSHA's requirement for breathing air to have at least 19.5 percent oxygen content. - 04/02/2007
- 1910.134(d)(2)(ii) - Use of smoke escape hoods meeting the ANSI-ISEA standard - 08/11/2010
- 1910.134(d)(2)(iii) - Applicability of OSHA's definition of oxygen-deficient atmosphere to Air Force facilities - 07/16/2024
- 1910.134(d)(2)(iii) - Clarification of OSHA denial of FirePASS's variance request and respiratory protection requirements in oxygen-deficient atmospheres. - 05/01/2008
- 1910.134(d)(2)(iii) - Clarification of OSHA's requirement for breathing air to have at least 19.5 percent oxygen content. - 04/02/2007
- 1910.134(d)(3) - Hooded versus tight-fitting respirators when complying with the Asbestos Standard - 07/18/2017
- 1910.134(d)(3)(i)(A) - APF for the combination pressure-demand, full-facepiece SAR with auxiliary SCBA - 11/04/2013
- 1910.134(d)(3)(i)(A) - Protection factors for respirators used in pharmaceutical industry: policy change. - 05/30/2002
- 1910.134(d)(3)(i)(A) - Use of powered-air purifying respirators (PAPR) for welding operations and assigned protection factor - 04/15/2021
- 1910.134(d)(3)(iii) - Selection of air purifying respirators for gases and vapors with poor warning properties (diisocyanates) - 07/18/2000
- 1910.134(d)(3)(iii)(B)(1) - Use of Chemical Cartridge Respirators for Protection Against Mercury Vapor - 11/15/1985
- 1910.134(d)(3)(iv)(B) - The use of particulate filters and respirators. - 05/05/1997
- 1910.134(e) - Acceptable use of an electronic medical questionnaire system to comply with 1910.134(e). - 08/16/2002
- 1910.134(e) - Clarification of a PLHCP under the Respiratory protection standard. - 01/02/1999
- 1910.134(e) - Clarification of the medical evaluation provisions of the revised respiratory protection standard. - 11/16/1998
- 1910.134(e) - Health care professional's discretion regarding medical evaluations and exams. - 10/16/1998
- 1910.134(e) - Mandatory annual blood work requirements in OSHA's Respiratory Protection and Ethylene Oxide standards - 06/12/2017
- 1910.134(e) - Medical evaluation not required for the use of escape only respirators. - 03/08/1999
- 1910.134(e) - Medical evaluation requirements under the respiratory protection standard - 10/05/1998
- 1910.134(e) - Medical evaluations must be performed prior to fit testing. - 03/05/1999
- 1910.134(e) - Medical Interpretation concerning exposure to H2S and respiratory protection with a perforated ear drum. - 05/14/1984
- 1910.134(e) - Pulmonary function testing training requirements and spirometer transmission of disease. - 06/17/1993
- 1910.134(e) - Recordkeeping and maintenance of respirator medical evaluations - 12/04/2014
- 1910.134(e) - Respiratory protection, medical surveillance, and training requirements under HAZWOPER - 09/24/2002
- 1910.134(e) - Voluntary use respirators - 04/26/2018
- 1910.134(e)(1) - Escape-only respirators - 09/04/2019
- 1910.134(e)(1) - Fit testing and medical monitoring requirements for wearers of filtering facepiece respirators. - 06/12/2002
- 1910.134(e)(2) - Respiratory protection: editing the medical questionnaire; medical questionnaire not always required. - 01/04/1999
- 1910.134(e)(2)(i) - Conduct of respiratory protection medical evaluations by medical technicians. - 10/16/1998
- 1910.134(e)(3) - Mandatory annual blood work requirements in OSHA's Respiratory Protection and Ethylene Oxide standards - 06/12/2017
- 1910.134(e)(5)(i) - Use of skin diving hood under respirator for bearded employee unacceptable. - 02/25/1982
- 1910.134(e)(6)(i) - Retention of Spirometry Records - 09/18/2019
- 1910.134(e)(6)(i)(B) - Mandatory annual blood work requirements in OSHA's Respiratory Protection and Ethylene Oxide standards - 06/12/2017
- 1910.134(f) - Appendix A requirements and techniques for fit testing respirators. - 08/27/1999
- 1910.134(f) - Qualitative and quantitative fit tests versus assigned protection factors - 05/23/2017
- 1910.134(f) - Requirements for fit testing employees before fire brigade training exercises. - 10/18/2004
- 1910.134(f) - Respirator fit test requirements - 02/08/2016
- 1910.134(f) - Respiratory protection, medical surveillance, and training requirements under HAZWOPER - 09/24/2002
- 1910.134(f) - The grimace step in respiratory protection fit-testing procedures. - 01/04/1999
- 1910.134(f) - The OSHA interpretation of respiratory protection requirements with regards to tuberculosis (TB) exposure. - 02/05/1996
- 1910.134(f) - Use of multi-station electric pump nebulizer and the squeeze bulb Bitrex for QLFT. - 03/08/2001
- 1910.134(f) - Voluntary use respirators - 04/26/2018
- 1910.134(f) - When to use qualitative or quantitative fit testing; storing SCBAs on fire trucks. - 11/16/1998
- 1910.134(f) - When to use quantitative and qualitative fit testing. - 01/15/1999
- 1910.134(f)(2) - Clarification of respirator costs, annual training, and "effective" seal checks. - 12/23/1998
- 1910.134(f)(2) - Fit testing and medical monitoring requirements for wearers of filtering facepiece respirators. - 06/12/2002
- 1910.134(f)(2) - OSHA requirements for respirator fit testing with and without facepiece accessories - 01/17/2017
- 1910.134(f)(2) - Respirator fit test requirements - 02/08/2016
- 1910.134(f)(6) - Respirators for voluntary use and cleaning respirators during fit testing. - 10/01/1999
- 1910.134(f)(7) - Fit testing for CBRN respirators. - 10/26/2011
- 1910.134(f)(7) - Fit testing requirements for respirators used for CBRN protection. - 12/27/2011
- 1910.134(f)(8) - Clarification on whether to use quantitative or qualitative fit-testing for full-facepiece PAPRs. - 07/23/2007
- 1910.134(f)(8) - Fit testing requirements for respirators used for CBRN protection. - 12/27/2011
- 1910.134(g) - Response to IDLH or Potential IDLH atmospheres. - 05/01/1995
- 1910.134(g) - Use of Air-Purifying Respirators In Dangerous Concentrations of Gases Or Vapors - 01/10/1990
- 1910.134(g)(1) - Facial hair and respirator fit - 05/09/2016
- 1910.134(g)(1)(i) - Beards may not interfere with face seal;alternative respirators for bearded employees. - 03/07/2003
- 1910.134(g)(1)(i) - Facial hair in the face sealing area is unacceptable. - 11/26/1985
- 1910.134(g)(1)(i) - Facial hair in the face sealing area is unacceptable. - 10/11/1984
- 1910.134(g)(1)(i) - Hair where the mask edges meet the skin is not permitted for wearers of 30 minute positive pressure SCBA respirators. - 08/18/1986
- 1910.134(g)(1)(i) - Protection provided by powered air-purifying respirators. - 03/20/1987
- 1910.134(g)(1)(i) - Use of the Racal "Breath-Easy 6" powered air purifying respirator with beards. - 07/27/1993
- 1910.134(g)(1)(i) - Workers cannot sign a release so they can wear a respirator with a beard. - 01/18/1984
- 1910.134(g)(1)(i)(A) - Appropriateness of using Mag-1 Eyewear eyeglass holders with full facepiece respirators and self-contained breathing apparatus (SCBA). - 09/20/1995
- 1910.134(g)(1)(i)(A) - Clarification on firefighters with facial hair who enter IDLH atmospheres and use a self-contained breathing apparatus. - 04/01/2011
- 1910.134(g)(1)(i)(A) - Facial hair and respirator fit - 05/09/2016
- 1910.134(g)(1)(i)(B) - Appropriateness of using Mag-1 Eyewear eyeglass holders with full facepiece respirators and self-contained breathing apparatus (SCBA). - 09/20/1995
- 1910.134(g)(1)(ii) - Facial hair in the face sealing area is unacceptable. - 11/26/1985
- 1910.134(g)(1)(ii) - Facial hair in the face sealing area is unacceptable. - 10/11/1984
- 1910.134(g)(1)(ii) - Hair where the mask edges meet the skin is not permitted for wearers of 30 minute positive pressure SCBA respirators. - 08/18/1986
- 1910.134(g)(1)(ii) - Protection provided by powered air-purifying respirators. - 03/20/1987
- 1910.134(g)(1)(iii) - Clarification of respirator costs, annual training, and "effective" seal checks. - 12/23/1998
- 1910.134(g)(1)(iii) - Facial hair in the face sealing area is unacceptable. - 11/26/1985
- 1910.134(g)(1)(iii) - Facial hair in the face sealing area is unacceptable. - 10/11/1984
- 1910.134(g)(1)(iii) - Fit testing and medical monitoring requirements for wearers of filtering facepiece respirators. - 06/12/2002
- 1910.134(g)(1)(iii) - Hair where the mask edges meet the skin is not permitted for wearers of 30 minute positive pressure SCBA respirators. - 08/18/1986
- 1910.134(g)(1)(iii) - Protection provided by powered air-purifying respirators. - 03/20/1987
- 1910.134(g)(3) - Permit-Required Confined Space Entry Requirements For IDLH and Non-IDLH Spaces - 07/17/2014
- 1910.134(g)(3) - Respiratory protection and emergency escape requirements for IDLH atmospheres. - 01/13/2003
- 1910.134(g)(4) - Classification of fires; respiratory protection to extinguish fires. - 07/08/2002
- 1910.134(g)(4) - Complying with the "two-in, two-out" policy for interior structural firefighting. - 03/12/1999
- 1910.134(g)(4) - Respiratory protecton standard two-in/two-out policy. - 12/15/1998
- 1910.134(g)(4) - Two-in/two-out procedure in firefighting/IDLH environments. - 04/29/1998
- 1910.134(g)(4) - Two-in/two-out rule for interior structural fire fighting. - 11/13/1998
- 1910.134(h) - Numerous questions on filtering facepiece/dusk mask respirators. - 11/22/2011
- 1910.134(h) - Use of Air-Purifying Respirators In Dangerous Concentrations of Gases Or Vapors - 01/10/1990
- 1910.134(h)(1) - Respirators for voluntary use and cleaning respirators during fit testing. - 10/01/1999
- 1910.134(h)(1)(iii) - Decontamination of SCBA second stage regulators. - 11/02/1998
- 1910.134(h)(2) - When to use qualitative or quantitative fit testing; storing SCBAs on fire trucks. - 11/16/1998
- 1910.134(i) - 1910.134(i) does not apply to portable breathing air compressors. - 08/13/1999
- 1910.134(i) - Breathing air: testing and carbon monoxide alarm. - 04/25/1994
- 1910.134(i) - Clarifications for breathing air quality and use - 05/31/2023
- 1910.134(i) - Respirator air quality standards do not apply where the NRC has jurisdiction - 03/06/1979
- 1910.134(i)(1)(i) - Cool-view welding helmets must meet Grade D breathing air requirements; Requirements for standard welding helmets. - 07/14/1981
- 1910.134(i)(1)(ii) - Clarifications for breathing air quality and use - 05/31/2023
- 1910.134(i)(4)(ii) - Using a "generic type" certificate of analysis for Grade D breathing air. - 02/05/1999
- 1910.134(i)(4)(iii) - Clarifications for breathing air quality and use - 05/31/2023
- 1910.134(i)(5)(ii) - Clarifications for breathing air quality and use - 05/31/2023
- 1910.134(i)(7) - Carbon Monoxide or High Temperature Alarm Requirement for Portable Breathing Air Compressors. - 07/05/1994
- 1910.134(i)(7) - Del-Monox air purifiers are unacceptable for testing carbon monoxide concentration for compressor breathing air. - 10/15/1981
- 1910.134(i)(8) - Couplings used in supplied air respirator systems. - 04/24/1986
- 1910.134(k) - Clarification of respirator costs, annual training, and "effective" seal checks. - 12/23/1998
- 1910.134(k) - OSHA Training Standards Policy Statements - 04/28/2010
- 1910.134(k) - Respirator fit test requirements - 02/08/2016
- 1910.134(k) - Use of Air-Purifying Respirators In Dangerous Concentrations of Gases Or Vapors - 01/10/1990
- 1910.134(k) - Use of smoke escape hoods meeting the ANSI-ISEA standard - 08/11/2010
- 1910.134(m) - Employee's rights upon termination to access to physician's written opinion and respirator fit test results. - 10/20/2005
- 1910.134(m) - Maintenance of medical evaluation and fit test records as required by the Respiratory Protection Standard. - 06/02/2009
- 1910.134(m)(2) - Employee's rights upon termination to access to physician's written opinion and respirator fit test results. - 10/20/2005
- 1910.134(m)(4) - Employee's rights upon termination to access to physician's written opinion and respirator fit test results. - 10/20/2005