1910.134(i)(4): Breathing Air Cylinder Requirements
Employers must make sure cylinders that supply breathing air to respirators are tested and maintained under DOT rules in 49 CFR part 180, that purchased air has a supplier's certificate showing it meets Grade D, and that moisture does not exceed a dew point of -50 F at 1 atmosphere.
Key takeaways
- 1910.134(i)(4) is part of OSHA's general industry standards (29 CFR Part 1910, Subpart I).
- OSHA cited it 43 times in the last 3 years, in 43 inspections, with $37,470 in current penalties.
- 1 death is linked to inspections that cited this rule.
- Most citations: IL (27), NJ (8), ME (4).
- Related part: 1910.134(i) Breathing air quality and use (149 citations).
- Free 5-minute toolbox talk for your crew below.
In this article
What this rule covers
29 CFR 1910.134(i)(4) is one requirement inside 1910.134 Respiratory protection, an OSHA general industry standard (Part 1910, Subpart I). It includes 3 sub-paragraphs. The official text below is copied word for word from the Electronic Code of Federal Regulations (eCFR). The numbers, injury cases and training on this page show how OSHA enforces it on real job sites.
Official text
(4) The employer shall ensure that cylinders used to supply breathing air to respirators meet the following requirements: 43 citations
(i) Cylinders are tested and maintained as prescribed in the Shipping Container Specification Regulations of the Department of Transportation (49 CFR part 180); Open (i)(4)(i) 18 citations
(ii) Cylinders of purchased breathing air have a certificate of analysis from the supplier that the breathing air meets the requirements for Grade D breathing air; and Open (i)(4)(ii) 3 citations
(iii) The moisture content in the cylinder does not exceed a dew point of −50 °F (−45.6 °C) at 1 atmosphere pressure. Open (i)(4)(iii)
Source: eCFR, text current as of 2026-10-15. Read all of 1910.134.
Injuries linked to this rule
1 death is linked to inspections where OSHA cited 1910.134(i)(4).
On April 11, 2024, an employee working as a fire fighter for a city fire department had been participating in fire fighter training from approximately from 7:30 a.m. to 4:00 p.m. The employee spent the majority of the day performing firefighting search drills while wearing…
Where and how often it was cited
| Year | Citations |
|---|---|
| 2023 | 2 |
| 2024 | 17 |
| 2025 | 16 |
| 2026 | 8 |
Top states: IL (27), NJ (8), ME (4), MI (1), PA (1)
Largest penalties
| Employer | Location | Penalty for this rule |
|---|---|---|
| JERSEY CITY FIRE DEPARTMENT, ENGINE 17 | JERSEY CITY, NJ | $7,000 |
| BOROUGH OF OLD TAPPAN | OLD TAPPAN, NJ | $7,000 |
| EMERSON FIRE DEPARTMENT | EMERSON, NJ | $6,300 |
| PITMAN FIRE CO. NO.1 | PITMAN, NJ | $5,000 |
| HIGHLAND CHEMICAL ENGINE COMPANY | PITMAN, NJ | $5,000 |
Free toolbox talk
A 5-minute crew talk on 1910.134(i)(4), plus alerts when this rule changes. Free.
OSHA interpretation letters
- Clarifications for breathing air quality and use (2023-05-31)
- Using a "generic type" certificate of analysis for Grade D breathing air. (1999-02-05)
Related parts of this rule
- 1910.134(i) Breathing air quality and use 149 citations
- 1910.134(i)(1) 34 citations
- 1910.134(i)(5) 34 citations
- 1910.134(i)(1)(ii) 31 citations
- 1910.134(i)(7) 30 citations
- 1910.134(i)(5)(iv) 24 citations
- 1910.134(i)(4)(i) 18 citations
- 1910.134(i)(8) 7 citations
- 1910.134(i)(4)(ii) 3 citations
- 1910.134(i)(5)(i) 3 citations
- 1910.134(i)(1)(ii)(A) 2 citations
- 1910.134(i)(1)(i)
Get your crew competent
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Frequently asked questions
What testing rules apply to breathing air cylinders?
They must be tested and maintained as prescribed in the DOT Shipping Container Specification Regulations, 49 CFR part 180.
What paperwork is needed for purchased breathing air?
A certificate of analysis from the supplier that the air meets Grade D breathing air requirements.
What is the moisture limit in the cylinder?
The moisture content must not exceed a dew point of -50 F (-45.6 C) at 1 atmosphere pressure.
About this page
Sources
- 29 CFR 1910.134 (eCFR), text current as of 2026-10-15
- U.S. Department of Labor enforcement data: OSHA inspections, citations and accident records, copied nightly; data as of 2026-10-21
3-year window. Federal OSHA only; state-plan rules are not counted. Plain-language text is a summary, not legal advice; the official text controls. Black Belt Safety is not part of OSHA or the Department of Labor.