42 CFR 84.200 - Inhalation and exhalation valves; minimum requirements.
(a) Inhalation and exhalation valves shall be provided where necessary and protected against distortion.
(b) Inhalation valves shall be designed and constructed to prevent excessive exhaled air from entering cartridges or adversely affecting canisters.
Title 42 published on 2014-10-01
no entries appear in the Federal Register after this date.