View all text of Subpart K [§ 84.170 - § 84.181]
§ 84.178 - Breath response type, airflow resistance test—PAPR classes HE and PAPR100.
Resistance to airflow will be measured with a breathing machine as described in § 84.88.
(a) Minimum inhalation resistance must be greater than zero mm of water-column height.
(b) Maximum exhalation resistance must be less than 89 mm of water-column height.