1910.106(d)(4)(iii): Wiring in Flammable Liquid Storage Rooms
Employers must make sure wiring and equipment in inside storage rooms for Category 1 or 2 flammable liquids, or Category 3 with a flashpoint below 100 F, are approved for Class I, Division 2 Hazardous Locations. For Category 3 at or above 100 F and Category 4 liquids, they must be approved for general use.
Key takeaways
- 1910.106(d)(4)(iii) is part of OSHA's general industry standards (29 CFR Part 1910, Subpart H).
- OSHA cited it 10 times in the last 3 years, in 10 inspections, with $4,706 in current penalties.
- Most citations: MI (5), IN (1), MO (1).
- Related part: 1910.106(d) Container and portable tank storage (357 citations).
- Free 5-minute toolbox talk for your crew below.
In this article
What this rule covers
29 CFR 1910.106(d)(4)(iii) ("Wiring") is one requirement inside 1910.106 Flammable liquids, an OSHA general industry standard (Part 1910, Subpart H). 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
(iii) Wiring. Electrical wiring and equipment located in inside storage rooms used for Category 1 or 2 flammable liquids, or Category 3 flammable liquids with a flashpoint below 100 °F (37.8 °C), shall be approved under subpart S of this part for Class I, Division 2 Hazardous Locations; for Category 3 flammable liquids with a flashpoint at or above 100 °F (37.8 °C) and Category 4 flammable liquids, shall be approved for general use. 10 citations
Source: eCFR, text current as of 2026-10-15. Read all of 1910.106.
Where and how often it was cited
| Year | Citations |
|---|---|
| 2023 | 3 |
| 2024 | 2 |
| 2025 | 3 |
| 2026 | 2 |
Top states: MI (5), IN (1), MO (1), IA (1), MA (1)
Largest penalties
| Employer | Location | Penalty for this rule |
|---|---|---|
| GOLDEN WEST ADVERTISING, INC | BOISE, ID | $3,940 |
| EXECUTIVE WOOD PRODUCTS, INC. | SULLIVAN, MO | $473 |
| IGNITION ARTS | INDIANAPOLIS, IN | $293 |
| FMFL FACILITIES LLC | BUCHANAN, MI | $0 |
| ENDLESS WEST | DETROIT, MI | $0 |
Free toolbox talk
A 5-minute crew talk on 1910.106(d)(4)(iii), plus alerts when this rule changes. Free.
OSHA interpretation letters
None exist. OSHA has not published a letter of interpretation for 1910.106(d)(4)(iii).
Related parts of this rule
- 1910.106(d) Container and portable tank storage 357 citations
- 1910.106(d)(2) Design, construction, and capacity of containers 125 citations
- 1910.106(d)(2)(i) General 83 citations
- 1910.106(d)(4) Design and construction of inside storage rooms 67 citations
- 1910.106(d)(3) Design, construction, and capacity of storage cabinets 65 citations
- 1910.106(d)(3)(ii) Fire resistance 59 citations
- 1910.106(d)(5) Storage inside building 55 citations
- 1910.106(d)(2)(iii) Size 39 citations
- 1910.106(d)(4)(i) Construction 26 citations
- 1910.106(d)(7) Fire control 23 citations
- 1910.106(d)(4)(iv) Ventilation 22 citations
- 1910.106(d)(6) Storage outside buildings 22 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
What wiring is needed for Category 1 or 2 liquids?
Wiring approved under subpart S for Class I, Division 2 Hazardous Locations.
What about Category 3 liquids?
Below 100 F (37.8 C) flashpoint, Class I, Division 2; at or above 100 F, approved for general use.
What about Category 4?
Approved for general use.
About this page
Sources
- 29 CFR 1910.106 (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.