(a) Resistance to airflow will be measured in the facepiece or mouthpiece of a gas mask mounted on a breathing machine both before and after each test conducted in accordance with Sec. Sec. 84.124, 84.125, and 84.126, with air flowing at a continuous rate of 85 liters per minute.
(b) The maximum allowable resistance requirements for gas masks are as follows:
Maximum Resistance
[mm. water-column height]------------------------------------------------------------------------
Inhalation
Type of gas mask -------------------------- Exhalation
Initial Final \1\------------------------------------------------------------------------Front-mounted or back-mounted 60 75 20
(without particulate filter)....Front-mounted or back-mounted 70 85 20
(with approved particulate
filter).........................Chin-style (without particulate 40 55 20
filter).........................Chin-style (with approved 65 80 20
particulate filter).............Escape (without particulate 60 75 20
filter).........................Escape (with approved particulate 70 85 20
filter).........................------------------------------------------------------------------------\1\ Measured at end of the service life specified in Tables 5, 6, and 7
of this subpart.