# Letters of Interpretation
1 - 1910.134(d)(2)(iii) - Applicability of OSHA's definition of oxygen-deficient atmosphere to Air Force facilities
2 - 1910.134(d)(1)(ii) - Clarifications for breathing air quality and use
3 - 1910.134(d)(1) - Respiratory protection against COVID-19 for employees with religiously mandated facial hair
4 - 1910.134(d)(3)(i)(A) - Use of powered-air purifying respirators (PAPR) for welding operations and assigned protection factor
5 - 1910.134(d)(3) - Hooded versus tight-fitting respirators when complying with the Asbestos Standard
6 - 1910.134(d), 1910.134(d)(3) - Hooded versus tight-fitting respirators when complying with the Asbestos Standard
7 - 1910.134(d) - Qualitative and quantitative fit tests versus assigned protection factors
8 - 1910.134(d)(1)(ii) - OSHA requirements for respirator fit testing with and without facepiece accessories
9 - 1910.134(d)(3)(i)(A) - APF for the combination pressure-demand, full-facepiece SAR with auxiliary SCBA
10 - 1910.134(d)(1)(iii) - Whether the Respiratory Protection standard requires personal air monitoring to identify and evaluate the respiratory hazards in the workplace.
11 - 1910.134(d)(1) - OSHA's decision not to provide a religious exemption from the respirator standard.
12 - 1910.134(d)(2)(ii) - Use of smoke escape hoods meeting the ANSI-ISEA standard
13 - 1910.134(d)(2)(iii) - Clarification of OSHA denial of FirePASS's variance request and respiratory protection requirements in oxygen-deficient atmospheres.
14 - 1910.134(d)(2)(iii) - Clarification of OSHA's requirement for breathing air to have at least 19.5 percent oxygen content.
15 - 1910.134(d)(2)(i)(B) - Clarification of OSHA's requirement for breathing air to have at least 19.5 percent oxygen content.
16 - 1910.134(d)(2)(i)(A) - Clarification of OSHA's requirement for breathing air to have at least 19.5 percent oxygen content.
17 - 1910.134(d)(1)(i) - Beards may not interfere with face seal;alternative respirators for bearded employees.
18 - 1910.134(d)(3)(i)(A) - Protection factors for respirators used in pharmaceutical industry: policy change.
19 - 1910.134(d)(1)(i) - Selection of air purifying respirators for gases and vapors with poor warning properties (diisocyanates)
20 - 1910.134(d)(3)(iii) - Selection of air purifying respirators for gases and vapors with poor warning properties (diisocyanates)
21 - 1910.134(d)(1)(ii) - Respirators for voluntary use and cleaning respirators during fit testing.
22 - 1910.134(d)(1)(ii) - Using combinations of respiratory protection not approved by NIOSH.
23 - 1910.134(d) - Assessing hazards to select eye and respiratory protection.
24 - 1910.134(d)(1)(ii) - NIOSH approved respirator during the period of an employee's escape from a chemical release of phosgene.
25 - 1910.134(d)(1)(ii) - SCBA cylinder interchangeability.
26 - 1910.134(d)(3)(iv)(B) - The use of particulate filters and respirators.
27 - 1910.134(d) - The relationship between OSHA standards and the usage of particulate respirators.
28 - 1910.134(d) - The OSHA interpretation of respiratory protection requirements with regards to tuberculosis (TB) exposure.
29 - 1910.134(d)(2) - Clarification on OSHA's policy regarding Immediately Dangerous to Life and Health since NIOSH has lowered several IDLH levels.
30 - 1910.134(d), 1910.134(d)(2) - Clarification on OSHA's policy regarding Immediately Dangerous to Life and Health since NIOSH has lowered several IDLH levels.
31 - 1910.134(d)(1)(ii) - Use of non-approved respirators and improper use of approved respirators
32 - 1910.134(d) - Use of Air-Purifying Respirators In Dangerous Concentrations of Gases Or Vapors
33 - 1910.134(d)(3)(iii)(B)(1) - Use of Chemical Cartridge Respirators for Protection Against Mercury Vapor