1910.307(c)(2)(i): Approval for the Specific Hazardous Substance
Electrical equipment in hazardous (classified) locations must be approved not only for the class of location but also for the ignitable or combustible properties of the specific gas, vapor, dust or fiber that will be present. NFPA 70 groups these hazards by their properties.
Key takeaways
- 1910.307(c)(2)(i) is part of OSHA's general industry standards (29 CFR Part 1910, Subpart S).
- OSHA cited it 31 times in the last 3 years, in 31 inspections, with $81,003 in current penalties.
- Most citations: MA (3), NC (3), FL (2).
- Related part: 1910.307(c) Electrical installations (146 citations).
- Free 5-minute toolbox talk for your crew below.
In this article
What this rule covers
29 CFR 1910.307(c)(2)(i) is one requirement inside 1910.307 Hazardous (classified) locations, an OSHA general industry standard (Part 1910, Subpart S). 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
(i) Equipment shall be approved not only for the class of location, but also for the ignitable or combustible properties of the specific gas, vapor, dust, or fiber that will be present. 31 citations
NFPA 70, the National Electrical Code, lists or defines hazardous gases, vapors, and dusts by “Groups” characterized by their ignitable or combustible properties.
Source: eCFR, text current as of 2026-10-15. Read all of 1910.307.
Where and how often it was cited
| Year | Citations |
|---|---|
| 2023 | 4 |
| 2024 | 8 |
| 2025 | 14 |
| 2026 | 5 |
Top states: MA (3), NC (3), FL (2), MO (2), IL (2)
Largest penalties
| Employer | Location | Penalty for this rule |
|---|---|---|
| DIAMOND SHAMROCK REFINING COMPANY, L.P. | THREE RIVERS, TX | $16,550 |
| SIMMONS ANIMAL NUTRITION, INC. | BRIDGEVILLE, DE | $12,500 |
| AIR LIQUIDE ADVANCED MATERIALS, INC. | HIGH SPRINGS, FL | $10,938 |
| XPRESS NATURAL GAS, LLC | MONTROSE, PA | $8,513 |
| SHAW'S SOUTHERN BELLE FROZEN FOODS, INC. | JACKSONVILLE, FL | $5,908 |
Free toolbox talk
A 5-minute crew talk on 1910.307(c)(2)(i), plus alerts when this rule changes. Free.
OSHA interpretation letters
None exist. OSHA has not published a letter of interpretation for 1910.307(c)(2)(i).
Related parts of this rule
- 1910.307(c) Electrical installations 146 citations
- 1910.307(c)(2) Approved for the hazardous (classified) location 32 citations
- 1910.307(c)(3) Safe for the hazardous (classified) location 17 citations
- 1910.307(c)(1) Intrinsically safe 9 citations
Get your crew competent
Trainers on Black Belt Safety: Marc Harvey, Dana Reyes
Trainers and suppliers: feature your business on this rule for $25/month.
Frequently asked questions
Is approval for the class enough?
No. Equipment must also be approved for the specific gas, vapor, dust or fiber present.
How are hazardous substances grouped?
NFPA 70, the National Electrical Code, lists them by Groups characterized by their ignitable or combustible properties.
Why does the specific substance matter?
Different gases, vapors and dusts ignite differently, so approval must match the substance.
About this page
Sources
- 29 CFR 1910.307 (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.