1910.106(d)(4)(i): Inside Flammable Liquid Storage Room Construction
Employers must build inside storage rooms for flammable liquids to the required fire-resistive rating. Openings to other rooms need noncombustible liquid-tight raised sills or ramps at least 4 inches high (or a floor at least 4 inches lower, or an open-grated trench draining to a safe place) and approved self-closing fire doors. The room must be liquid-tight where walls meet the floor.
Key takeaways
- 1910.106(d)(4)(i) is part of OSHA's general industry standards (29 CFR Part 1910, Subpart H).
- OSHA cited it 26 times in the last 3 years, in 26 inspections, with $103,691 in current penalties.
- Most citations: PA (7), WI (5), MI (3).
- 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)(i) ("Construction") 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
(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. 26 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 | 4 |
| 2024 | 7 |
| 2025 | 10 |
| 2026 | 5 |
Top states: PA (7), WI (5), MI (3), OK (2), VA (2)
Largest penalties
| Employer | Location | Penalty for this rule |
|---|---|---|
| CUSTOM CONTAINER SOLUTIONS, LLC | MILTON, PA | $14,000 |
| WIKOFF COLOR CORPORATION | LISBON, WI | $9,000 |
| RANA MEAL SOLUTIONS, LLC | BARTLETT, IL | $8,593 |
| JOHNSON THERMAL SYSTEMS, LLC. | CALDWELL, ID | $8,512 |
| 24M TECHNOLOGIES, INC. | CAMBRIDGE, MA | $8,511 |
Free toolbox talk
A 5-minute crew talk on 1910.106(d)(4)(i), 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)(i).
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)(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
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
How high must the sill or ramp be?
At least 4 inches, or the storage floor must be at least 4 inches below the surrounding floor.
What doors are required?
Approved self-closing fire doors on openings.
Can wood be used inside?
Wood at least 1 inch nominal thickness may be used for shelving, racks, dunnage, scuffboards, floor overlay and similar uses.
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.