---
kind: "unit"
title: "42"
title_heading: "Public Health"
key: "chI/subchG/part84/subpartK"
level: "subpart"
label: "Subpart K"
heading: "Air-Purifying Particulate Respirators"
release: "ecfr-current"
date: "2026-08-27"
url: "https://uscodex.org/cfr/42/chI-subchG-part84-subpartK"
sections_count: 12
---

# Subpart K — Air-Purifying Particulate Respirators

Title 42 C.F.R. — Public Health › Chapter I — Public Health Service, Department of Health and Human Services › Subchapter G — Occupational Safety and Health Research and Related Activities › Part 84 — Approval of Respiratory Protective Devices

## Sections

- [§84.170. Air-purifying particulate respirators; description.](/cfr/42/84.170.md)
- [§84.171. Required components and attributes.](/cfr/42/84.171.md)
- [§84.172. Airflow resistance test.](/cfr/42/84.172.md)
- [§84.173. Exhalation valve leakage test.](/cfr/42/84.173.md)
- [§84.174. Filter efficiency level determination test—non-powered series N, R, and P filtration.](/cfr/42/84.174.md)
- [§84.175. Instantaneous filter efficiency level determination test—PAPR series HE, PAPR100-N, and PAPR100-P filtration.](/cfr/42/84.175.md)
- [§84.176. Fit test—PAPR classes HE and PAPR100.](/cfr/42/84.176.md)
- [§84.177. Total noise level test—PAPR classes HE and PAPR100.](/cfr/42/84.177.md)
- [§84.178. Breath response type, airflow resistance test—PAPR classes HE and PAPR100.](/cfr/42/84.178.md)
- [§84.179. Silica dust loading test—PAPR series HE filtration.](/cfr/42/84.179.md)
- [§84.180. Particulate loading test—PAPR series PAPR100-N and PAPR100-P filtration.](/cfr/42/84.180.md)
- [§84.181. Communication performance test—PAPR class PAPR100.](/cfr/42/84.181.md)