42 C.F.R. § 84.92 Exhalation valve leakage test.
Title 42 - Public Health
(a) Dry exhalation valves and valve seats will be subjected to a suction of 25 mm. (1 inch) water-column height while in a normal operating position. (b) Leakage between the valve and the valve seat shall not exceed 30 milliliters per minute.
Title 42: Public Health
PART 84—APPROVAL OF RESPIRATORY PROTECTIVE DEVICES
Subpart H—Self-Contained Breathing Apparatus
§ 84.92 Exhalation valve leakage test.