42 CFR 84.91
§ 84.91 Breathing resistance test; exhalation.
United States · 42 CFR — Public Health · Status: effective
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- Citation
- 42 CFR 84.91, § 84.91 Breathing resistance test; exhalation, United States, version 1 as recorded 2026-07-09, yourstate.us, https://yourstate.us/provision/201708
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Full text
(a) Resistance to exhalation airflow will be measured in the facepiece or mouthpiece of open-circuit apparatus with air flowing at a continuous rate of 85 liters per minute.
(b) The exhalation resistance of demand apparatus shall not exceed 25 mm. (1 inch) water-column height.
(c) The exhalation resistance of pressure-demand apparatus shall not exceed the static pressure in the facepiece by more than 51 mm. (2 inches) water-column height.
(d) The static pressure (at zero flow) in the facepiece shall not exceed 38 mm. (1.5 inches) water-column height.
(e) Resistance to exhalation airflow will be measured in the facepiece or mouthpiece of closed-circuit apparatus with a breathing machine as described in § 84.88, and the exhalation resistance shall not exceed 51 mm. (2 inches) water-column height.
Legislative history
This is a federal regulation, adopted through agency rulemaking under the Administrative Procedure Act — not enacted by a recorded vote of Congress.