1910.146(d)(3)(iv): Purge, Inert, Flush or Ventilate Permit Spaces
As part of the permit space program, employers must purge, inert, flush or ventilate the permit space as necessary to eliminate or control atmospheric hazards.
Key takeaways
- 1910.146(d)(3)(iv) is part of OSHA's general industry standards (29 CFR Part 1910, Subpart J).
- OSHA cited it 8 times in the last 3 years, in 8 inspections, with $21,389 in current penalties.
- 1 death is linked to inspections that cited this rule.
- Related part: 1910.146(d) Permit-required confined space program (480 citations).
- Free 5-minute toolbox talk for your crew below.
In this article
What this rule covers
29 CFR 1910.146(d)(3)(iv) is one requirement inside 1910.146 Permit-required confined spaces, an OSHA general industry standard (Part 1910, Subpart J). 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
(iv) Purging, inerting, flushing, or ventilating the permit space as necessary to eliminate or control atmospheric hazards; 8 citations
Source: eCFR, text current as of 2026-10-15. Read all of 1910.146.
Injuries linked to this rule
1 death is linked to inspections where OSHA cited 1910.146(d)(3)(iv).
At approximately 9:34 a.m. on January 10, 2025, an employee was directed to enter a 23,737-gallon rail tank car containing residues of PCBs and transformer oil to obtain wipe samples of the interior surfaces. The rail tank car was a permit-required confined space. The employee…
Where and how often it was cited
Free toolbox talk
A 5-minute crew talk on 1910.146(d)(3)(iv), plus alerts when this rule changes. Free.
OSHA interpretation letters
None exist. OSHA has not published a letter of interpretation for 1910.146(d)(3)(iv).
Related parts of this rule
- 1910.146(d) Permit-required confined space program 480 citations
- 1910.146(d)(3) 107 citations
- 1910.146(d)(5) 91 citations
- 1910.146(d)(4) 66 citations
- 1910.146(d)(9) 63 citations
- 1910.146(d)(5)(i) 58 citations
- 1910.146(d)(2) 40 citations
- 1910.146(d)(4)(i) 33 citations
- 1910.146(d)(6) 31 citations
- 1910.146(d)(14) 23 citations
- 1910.146(d)(10) 17 citations
- 1910.146(d)(1) 16 citations
Get your crew competent
Trainers on Black Belt Safety: Marc Harvey, Dana Reyes
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Frequently asked questions
How are atmospheric hazards controlled in permit spaces?
By purging, inerting, flushing or ventilating the space as necessary.
Is ventilation always required?
These steps are done as necessary to eliminate or control atmospheric hazards.
What is the goal?
To eliminate or control atmospheric hazards.
About this page
Sources
- 29 CFR 1910.146 (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 2026-10-20
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.