84.1149—Airflow resistance tests; all dust, fume, and mist respirators; minimum requirements.

(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 §§ 84.1144 through 84.1147.

(b) The maximum allowable resistance requirements for dust, fume, and mist respirators are as follows:

Maximum Resistance

Type of respirator	Initial inhalation	Final inhalation	Exhalation
[mm. water-column height]
Pneumoconiosis- and fibrosis-producing dusts, or dusts and mists	12	15	15
Dust, fume, and mist, with single-use filter	30	50	20
Dust, fume, and mist, with reusable filter	20	40	20
Radon daughter	18	1 25	15
Asbestos dust and mist	18	25	15
1 Measured after silica dust test described in § 84.1144 .

CFR

84.1149—Airflow resistance tests; all dust, fume, and mist respirators; minimum requirements.