42 C.F.R. § 84.1137 Inhalation and exhalation valves; minimum requirements.
Title 42 - Public Health
(a) Inhalation and exhalation valves shall be protected against distortion. (b) Inhalation valves shall be designed and constructed and provided where necessary to prevent excessive exhaled air from adversely affecting filters, cartridges, and canisters, except where filters of dust, fume, and mist respirators are specifically designed to resist moisture as prescribed in §84.1145. (c) Exhalation valves shall be: (1) Provided where necessary; (2) Protected against damage and external influence; and (3) Designed and constructed to prevent inward leakage of contaminated air.
Title 42: Public Health
PART 84—APPROVAL OF RESPIRATORY PROTECTIVE DEVICES
Subpart KK—Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High Efficiency Respirators and Combination Gas Masks
§ 84.1137 Inhalation and exhalation valves; minimum requirements.
