1910.305(e): Electrical Enclosures for Damp or Wet Locations
Employers must install cabinets, boxes, fittings and panelboard enclosures in damp or wet locations so water cannot enter and collect, mounted with at least 6.35 mm (0.25 in.) of airspace from the wall, except nonmetallic enclosures on concrete, masonry, tile or similar surfaces. Enclosures in wet locations must be weatherproof, and switches, breakers and switchboards in wet locations need weatherproof enclosures.
Key takeaways
- 1910.305(e) is part of OSHA's general industry standards (29 CFR Part 1910, Subpart S).
- OSHA cited it 93 times in the last 3 years, in 92 inspections, with $152,235 in current penalties.
- Most citations: NY (20), NJ (8), CT (7).
- Related part: 1910.305(e)(1) Cabinets, cutout boxes, fittings, boxes, and panelboard enclosures (85 citations).
- Free 5-minute toolbox talk for your crew below.
In this article
What this rule covers
29 CFR 1910.305(e) ("Enclosures for damp or wet locations") is one requirement inside 1910.305 Wiring methods, components, and equipment for general use, an OSHA general industry standard (Part 1910, Subpart S). It includes 2 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
(e) Enclosures for damp or wet locations — 93 citations
(1) Cabinets, cutout boxes, fittings, boxes, and panelboard enclosures. Cabinets, cutout boxes, fittings, boxes, and panelboard enclosures in damp or wet locations shall be installed so as to prevent moisture or water from entering and accumulating within the enclosures and shall be mounted so there is at least 6.35-mm (0.25-in.) airspace between the enclosure and the wall or other supporting surface. However, nonmetallic enclosures may be installed without the airspace on a concrete, masonry, tile, or similar surface. The enclosures shall be weatherproof in wet locations. Open (e)(1) 85 citations
(2) Switches, circuit breakers, and switchboards. Switches, circuit breakers, and switchboards installed in wet locations shall be enclosed in weatherproof enclosures. 8 citations
Source: eCFR, text current as of 2026-10-15. Read all of 1910.305.
Where and how often it was cited
| Year | Citations |
|---|---|
| 2023 | 9 |
| 2024 | 36 |
| 2025 | 29 |
| 2026 | 19 |
Top states: NY (20), NJ (8), CT (7), MN (7), VA (6)
Largest penalties
| Employer | Location | Penalty for this rule |
|---|---|---|
| DTOP | PONCE, PR | $14,000 |
| EVERGREEN RECYCLING, LLC | ALBANY, NY | $10,758 |
| PPR | CATANO, PR | $9,457 |
| 159108 - COUNTY OF CASWELL SOLID WASTE | YANCEYVILLE, NC | $8,000 |
| KRAFT HEINZ | MUSCATINE, IA | $7,813 |
Free toolbox talk
A 5-minute crew talk on 1910.305(e), plus alerts when this rule changes. Free.
OSHA interpretation letters
None exist. OSHA has not published a letter of interpretation for 1910.305(e).
Related parts of this rule
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Frequently asked questions
How much airspace is required behind enclosures in wet or damp locations?
At least 6.35 mm (0.25 in.) between the enclosure and the wall or supporting surface.
What about switches and breakers in wet locations?
They must be enclosed in weatherproof enclosures.
Can nonmetallic boxes be mounted flat against concrete?
Yes. Nonmetallic enclosures may be installed without the airspace on concrete, masonry, tile or similar surfaces.
About this page
Sources
- 29 CFR 1910.305 (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.