1910.94(a)(4): Exhaust Ventilation for Abrasive Blasting
Abrasive blasting exhaust systems must be built, installed, inspected and maintained to ANSI Z9.2-1960 and Z33.1-1961. Dust leaks must be repaired as soon as possible, and static pressure checked at completion and periodically, with cleaning when a change shows blockage. Recirculated abrasive needs a separator, and exhaust air must pass through dust collectors that empty without contaminating other areas.
Key takeaways
- 1910.94(a)(4) is part of OSHA's general industry standards (29 CFR Part 1910, Subpart G).
- OSHA cited it 19 times in the last 3 years, in 15 inspections, with $48,876 in current penalties.
- Most citations: TX (4), TN (3), AL (3).
- Related part: 1910.94(a) Abrasive blasting (65 citations).
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In this article
What this rule covers
29 CFR 1910.94(a)(4) ("Exhaust ventilation systems") is one requirement inside 1910.94 Ventilation, an OSHA general industry standard (Part 1910, Subpart G). 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) Exhaust ventilation systems. 19 citations
(i) The construction, installation, inspection, and maintenance of exhaust systems shall conform to the principles and requirements set forth in American National Standard Fundamentals Governing the Design and Operation of Local Exhaust Systems, Z9.2-1960, and ANSI Z33.1-1961, which is incorporated by reference as specified in § 1910.6. Open (a)(4)(i) 14 citations
(a) When dust leaks are noted, repairs shall be made as soon as possible.
(b) The static pressure drop at the exhaust ducts leading from the equipment shall be checked when the installation is completed and periodically thereafter to assure continued satisfactory operation. Whenever an appreciable change in the pressure drop indicates a partial blockage, the system shall be cleaned and returned to normal operating condition.
(ii) In installations where the abrasive is recirculated, the exhaust ventilation system for the blasting enclosure shall not be relied upon for the removal of fines from the spent abrasive instead of an abrasive separator. An abrasive separator shall be provided for the purpose. 3 citations
(iii) The air exhausted from blast-cleaning equipment shall be discharged through dust collecting equipment. Dust collectors shall be set up so that the accumulated dust can be emptied and removed without contaminating other working areas. 2 citations
Source: eCFR, text current as of 2026-10-15. Read all of 1910.94.
Export the list: 15 inspections cited 1910.94(a)(4) in the last 3 years, with employer, location, penalty and date.
Purple Belt, $59/moWhere and how often it was cited
| Year | Citations |
|---|---|
| 2024 | 7 |
| 2025 | 9 |
| 2026 | 3 |
Top states: TX (4), TN (3), AL (3), OK (2), ID (2)
Largest penalties
| Employer | Location | Penalty for this rule |
|---|---|---|
| VTCU, CORP. | POCATELLO, ID | $27,898 |
| LASER SPECIALTIES INC. | TULSA, OK | $5,808 |
| TEWA LLC | VINTON, TX | $4,000 |
| PINTER MEMORIALS INC | BESSEMER, AL | $3,376 |
| HENOCK CONSTRUCTION, LLC | SAN ANTONIO, TX | $2,600 |
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A 5-minute crew talk on 1910.94(a)(4), plus alerts when this rule changes. Free.
OSHA interpretation letters
None exist. OSHA has not published a letter of interpretation for 1910.94(a)(4).
Related parts of this rule
- 1910.94(a) Abrasive blasting 65 citations
- 1910.94(a)(5) Personal protective equipment 18 citations
- 1910.94(a)(3)(i) 15 citations
- 1910.94(a)(3) Blast-cleaning enclosures 15 citations
- 1910.94(a)(4)(i) 14 citations
- 1910.94(a)(5)(ii) 4 citations
- 1910.94(a)(5)(i) 4 citations
- 1910.94(a)(2) Dust hazards from abrasive blasting 3 citations
- 1910.94(a)(1) Definitions applicable to this paragraph 1 citations
- 1910.94(a)(1)(ii) Abrasive-blasting respirator
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Frequently asked questions
What must be done when dust leaks are found?
Repairs shall be made as soon as possible.
How is blockage detected?
By checking static pressure drop at the exhaust ducts at completion and periodically; an appreciable change indicating partial blockage means the system must be cleaned.
Can the exhaust system remove fines from recirculated abrasive?
No. An abrasive separator must be provided for that purpose.
About this page
Sources
- 29 CFR 1910.94 (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 2026-11-06
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.