42 CFR § 84.122 - Breathing resistance test; minimum requirements.

---
identifier: "/us/cfr/t42/s84.122"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "42 CFR § 84.122 - Breathing resistance test; minimum requirements."
title_number: 42
title_name: "Public Health"
section_number: "84.122"
section_name: "Breathing resistance test; minimum requirements."
chapter_name: "PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES"
subchapter_number: "G"
subchapter_name: "OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES"
part_number: "84"
part_name: "APPROVAL OF RESPIRATORY PROTECTIVE DEVICES"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "29 U.S.C. 651  30 U.S.C. 3, 5, 7, 811, 842(h), 844."
regulatory_source: "60 FR 30355, June 8, 1995, unless otherwise noted."
cfr_part: "84"
---


# 84.122 Breathing resistance test; minimum requirements.

(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 §§ 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]

|  |  |  |  |
| --- | --- | --- | --- |
| Front-mounted or back-mounted (without particulate filter) | 60 | 75 | 20 |
| Front-mounted or back-mounted (with approved particulate filter) | 70 | 85 | 20 |
| Chin-style (without particulate filter) | 40 | 55 | 20 |
| Chin-style (with approved particulate filter) | 65 | 80 | 20 |
| Escape (without particulate filter) | 60 | 75 | 20 |
| Escape (with approved particulate filter) | 70 | 85 | 20 |
| Measured at end of the service life specified in Tables 5, 6, and 7 of this subpart. |  |  |  |