(a) Resistance to airflow will be measured in the facepiece, mouthpiece, hood, or helmet of a dust, fume, or mist respirator mounted on a test fixture with air flowing at a continuous rate of 85 liters per minute, both before and after each test conducted in accordance with Sec. Sec. 84.1144 through 84.1147.
(b) The maximum allowable resistance requirements for dust, fume, and mist respirators are as follows:
Maximum Resistance
[mm. water-column height]------------------------------------------------------------------------
Initial Final
Type of respirator inhalation inhalation Exhalation------------------------------------------------------------------------Pneumoconiosis- and fibrosis- 12 15 15
producing dusts, or dusts and
mists...........................Dust, fume, and mist, with single- 30 50 20
use filter......................Dust, fume, and mist, with 20 40 20
reusable filter.................Radon daughter................... 18 \1\ 25 15Asbestos dust and mist........... 18 25 15------------------------------------------------------------------------\1\ Measured after silica dust test described in Sec. 84.1144.