---
kind: "unit"
title: "42"
title_heading: "Public Health"
key: "chI/subchG/part84/subpartO"
level: "subpart"
label: "Subpart O"
heading: "Closed-Circuit Escape Respirators"
release: "ecfr-current"
date: "2026-08-27"
url: "https://uscodex.org/cfr/42/chI-subchG-part84-subpartO"
sections_count: 12
---

# Subpart O — Closed-Circuit Escape 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

- [§84.300. Closed-circuit escape respirator; description.](/cfr/42/84.300.md)
- [§84.301. Applicability to new and previously approved CCERs.](/cfr/42/84.301.md)
- [§84.302. Required components, attributes, and instructions.](/cfr/42/84.302.md)
- [§84.303. General testing conditions and requirements.](/cfr/42/84.303.md)
- [§84.304. Capacity test requirements.](/cfr/42/84.304.md)
- [§84.305. Performance test requirements.](/cfr/42/84.305.md)
- [§84.306. Wearability test requirements.](/cfr/42/84.306.md)
- [§84.307. Environmental treatments.](/cfr/42/84.307.md)
- [§84.308. Additional testing.](/cfr/42/84.308.md)
- [§84.309. Additional testing and requirements for dockable CCERs.](/cfr/42/84.309.md)
- [§84.310. Post-approval testing.](/cfr/42/84.310.md)
- [§84.311. Registration of CCER units upon purchase.](/cfr/42/84.311.md)