1910.106(d)(4): Inside Storage Rooms for Flammable Liquids
Employers must build inside storage rooms for flammable liquids to the required fire-resistive rating, with self-closing fire doors, raised sills or ramps at least 4 inches high (or a floor 4 inches lower, or a draining trench), and liquid-tight wall-floor joints. Storage amounts and room sizes must follow Table H-13.
Key takeaways
- 1910.106(d)(4) is part of OSHA's general industry standards (29 CFR Part 1910, Subpart H).
- OSHA cited it 67 times in the last 3 years, in 47 inspections, with $177,859 in current penalties.
- Most citations: MI (11), PA (7), WI (7).
- 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) ("Design and construction of inside storage rooms") is one requirement inside 1910.106 Flammable liquids, an OSHA general industry standard (Part 1910, Subpart H). It includes 5 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) Design and construction of inside storage rooms — 67 citations
(i) Construction. Inside storage rooms shall be constructed to meet the required fire-resistive rating for their use. Such construction shall comply with the test specifications set forth in Standard Methods of Fire Tests of Building Construction and Materials, NFPA 251-1969. Where an automatic sprinkler system is provided, the system shall be designed and installed in an acceptable manner. Openings to other rooms or buildings shall be provided with noncombustible liquid-tight raised sills or ramps at least 4 inches in height, or the floor in the storage area shall be at least 4 inches below the surrounding floor. Openings shall be provided with approved self-closing fire doors. The room shall be liquid-tight where the walls join the floor. A permissible alternate to the sill or ramp is an open-grated trench inside of the room which drains to a safe location. Where other portions of the building or other properties are exposed, windows shall be protected as set forth in the Standard for Fire Doors and Windows, NFPA No. 80-1968, which is incorporated by reference as specified in § 1910.6, for Class E or F openings. Wood at least 1 inch nominal thickness may be used for shelving, racks, dunnage, scuffboards, floor overlay, and similar installations. Open (d)(4)(i) 26 citations
(ii) Rating and capacity. Storage in inside storage rooms shall comply with Table H-13. 1 citations
| Fire protection 1 provided | Fire resistance | Maximum size | Total allowable quantities (gals./sq. ft./floor area) |
|---|---|---|---|
| Yes | 2 hours | 500 sq. ft | 10 |
| No | 2 hours | 500 sq. ft | 5 |
| Yes | 1 hour | 150 sq. ft | 4 |
| No | 1 hour | 150 sq. ft | 2 |
| 1 Fire protection system shall be sprinkler, water spray, carbon dioxide, or other system. | |||
(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. Open (d)(4)(iii) 10 citations
(iv) Ventilation. Every inside storage room shall be provided with either a gravity or a mechanical exhaust ventilation system. Such system shall be designed to provide for a complete change of air within the room at least six times per hour. If a mechanical exhaust system is used, it shall be controlled by a switch located outside of the door. The ventilating equipment and any lighting fixtures shall be operated by the same switch. A pilot light shall be installed adjacent to the switch if Category 1 or 2 flammable liquids, or Category 3 flammable liquids with a flashpoint below 100 °F (37.8 °C), are dispensed within the room. Where gravity ventilation is provided, the fresh air intake, as well as the exhaust outlet from the room, shall be on the exterior of the building in which the room is located. Open (d)(4)(iv) 22 citations
(v) Storage in inside storage rooms. In every inside storage room there shall be maintained one clear aisle at least 3 feet wide. Containers over 30 gallons capacity shall not be stacked one upon the other. Dispensing shall be by approved pump or self-closing faucet only. 5 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 | 10 |
| 2024 | 18 |
| 2025 | 26 |
| 2026 | 13 |
Top states: MI (11), PA (7), WI (7), VA (7), OK (4)
Largest penalties
| Employer | Location | Penalty for this rule |
|---|---|---|
| CUSTOM CONTAINER SOLUTIONS, LLC | MILTON, PA | $14,000 |
| THE GOODYEAR TIRE & RUBBER COMPANY | DANVILLE, VA | $13,415 |
| KAIZEN AUTO CARE, LLC | BRIGHTON, CO | $9,930 |
| WIKOFF COLOR CORPORATION | LISBON, WI | $9,000 |
| RANA MEAL SOLUTIONS, LLC | BARTLETT, IL | $8,593 |
Free toolbox talk
A 5-minute crew talk on 1910.106(d)(4), plus alerts when this rule changes. Free.
OSHA interpretation letters
- Applicability of OSHA standards to formaldehyde exposures in laboratories (2017-03-23)
- Spray booth requirements including automatic sprinkler systems, relationship to NFPA 33 requirements, and paint storage. (2004-08-12)
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)(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
- 1910.106(d)(5)(i) Egress 20 citations
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Frequently asked questions
How high must the sill or ramp be?
At least 4 inches in height, or the floor in the storage area must be at least 4 inches below the surrounding floor.
What kind of doors are required?
Approved self-closing fire doors on openings.
Where are storage limits listed?
In Table H-13, based on fire protection, fire resistance and room size.
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.