# DANGEROUS WHEN WET placard.

**Citation:** 49 CFR 172.548  
**Type / status:** regulation / current  
**Agency:** Pipeline and Hazardous Materials Safety Administration  
**Effective:** 2026-08-18  
**Published:** Not stated

(a) Except for size and color, the DANGEROUS WHEN WET placard must be as follows:

(b) In addition to complying with § 172.519, the background color on the DANGEROUS WHEN WET placard must be blue. The letters in the words “WHEN WET” must be at least 25 mm (1.0 inches) high. The symbol, text, class n

## Document text

(a) Except for size and color, the DANGEROUS WHEN WET placard must be as follows:

(b) In addition to complying with § 172.519, the background color on the DANGEROUS WHEN WET placard must be blue. The letters in the words “WHEN WET” must be at least 25 mm (1.0 inches) high. The symbol, text, class number and inner border must be white.

[Amdt. 172-123, 56 FR 66263, Dec. 20, 1991]

## Provenance

- Official: Yes
- Source: <https://www.ecfr.gov/on/2026-08-18/title-49/section-172.548>
- Source ID: `ecfr`
- SHA-256: `3c235f1642a69312783ab6538c372694b5b2a5218e71028fd6731cbe09bc61cd`
- Retrieved: 2026-08-20T05:45:59.130Z
- Exported: 2026-08-23T02:22:02.702Z
- Document slug: `49-cfr-172-548`

### Source metadata

```json
{
  "cfrTitle": 49,
  "part": "172",
  "section": "172.548",
  "subpart": "Subpart F—Placarding",
  "corpusVersion": "2026-08-18",
  "jurisdiction": "US"
}
```