Letters of Interpretation

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.

These letters of interpretation and the standards they address may not apply to OSHA State Plans. State Plans are required to have standards and enforcement programs that are at least as effective as OSHA's and may have different or additional requirements. Please see OSHA-approved State Plans for more information.

NOTICE:

How to Request a Letter of Interpretation

Filters


Date Title Standard Number
Whether the respiratory protection medical evaluation may consider factors beyond respirator use 1910.134, 1910.134(c), 1910.134(e), 1910.134(e)(5), 1910.134(e)(5)(i), 1910.134(e)(5)(iii), 1910.134(e)(6), 1910.134(e)(6)(i)(A)
Applicability of OSHA's definition of oxygen-deficient atmosphere to Air Force facilities 1910.134, 1910.134(d)(2)(iii), 1960, 1960.1, 1960.1(e)
Clarifications for breathing air quality and use 1910.134, 1910.134(d)(1)(ii), 1910.134(i), 1910.134(i)(1)(ii), 1910.134(i)(4)(iii), 1910.134(i)(5)(ii)
COVID-19 Focused Inspection Initiative in Healthcare 1904, 1910.132, 1910.134, 1910.502, 1910.1020
Respiratory protection against COVID-19 for employees with religiously mandated facial hair 1910.134, 1910.134(d)(1), 1910.502, 1910.502(f)(2)(i), 1910.502(f)(3)(i), 1910.504, 1910.504(d)(2)(ii)
Heat Initiative: Inspection Guidance 1904.7(b)(5), 1910.132, 1910.134, 1910.141, 1910.1020, 1915.88, 1917.127, 1918.95, 1926.20, 1926.21, 1926.51, 1928.110
Updated Interim Enforcement Response Plan for Coronavirus Disease 2019 (COVID-19) 1910.132, 1910.134, 1910.141, 1910.145, 1910.1020
Use of powered-air purifying respirators (PAPR) for welding operations and assigned protection factor 1910.134(d)(3)(i)(A)
Temporary Enforcement Guidance – Tight-Fitting Powered Air Purifying Respirators (PAPRs) Used During the Coronavirus Disease 2019 (COVID-19) Pandemic 1910.134, 1910.134(f)(2)
Enforcement Guidance on Decontamination of Filtering Facepiece Respirators in Healthcare During the Coronavirus Disease 2019 (COVID-19) Pandemic 1910.134, 1910.134(d)(1)(ii)
Discretion in Enforcement when Considering an Employer's Good Faith Efforts During the Coronavirus Disease 2019 (COVID-19) Pandemic 1910.95(g)(6), 1910.119(e)(6), 1910.120(e)(8), 1910.120(p)(7), 1910.120(q)(5), 1910.120(q)(7), 1910.134(f)(2), 1910.134(k), 1910.1048(l)(4), 1919.15, 1926.1412(f)
Expanded Temporary Enforcement Guidance on Respiratory Protection Fit-Testing for N95 Filtering Facepieces in All Industries During the Coronavirus Disease 2019 (COVID-19) Pandemic 1910.134, 1910.134(f)(2)
Enforcement Guidance for Respiratory Protection and the N95 Shortage Due to the Coronavirus Disease 2019 (COVID-19) Pandemic 1910.134(d)(1)(ii), 1910.134(f)(2), 1910.134 App B-1
Enforcement Guidance for Use of Respiratory Protection Equipment Certified under Standards of Other Countries or Jurisdictions During the Coronavirus Disease 2019 (COVID-19) Pandemic 1910.134(f)(2)
Temporary Enforcement Guidance - Healthcare Respiratory Protection Annual Fit-Testing for N95 Filtering Facepieces During the COVID-19 Outbreak 1910.134(d)(1)(ii)
Retention of Spirometry Records 1910.1020(c)(6)(i)(B), 1910.1020(b)(3), 1910.1020(d), 1910.1053, 1910.1053(i)(6), 1926.1153, 1926.1153(h)(6), 1910.134(e)(6)(i)
Escape-only respirators 1910.134, 1910.134(c)(1), 1910.134(e)(1), 1910.120
Voluntary use respirators 1910.134, 1910.134(c)(2), 1910.134(c)(4), 1910.134(f), 1910.134(e)
Filtering facepiece respirators and medical evaluations 1910.134(b), 1910.134(c)(2), 1910.134 App D
Voluntary use of surgical masks 1910.134