42 C.F.R. § 84.177 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, except where filters are specifically designed to resist moisture. (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 K—Non-Powered Air-Purifying Particulate Respirators
§ 84.177 Inhalation and exhalation valves; minimum requirements.
