# Placarding for subsidiary hazards.

**Citation:** 49 CFR 172.505  
**Type / status:** regulation / current  
**Agency:** Pipeline and Hazardous Materials Safety Administration  
**Effective:** 2026-08-18  
**Published:** Not stated

(a) Each transport vehicle, freight container, portable tank, unit load device, or rail car that contains a poisonous material subject to the “Poison Inhalation Hazard” shipping description of § 172.203(m) must be placarded with a POISON INHALATION HAZARD or POISON GAS placard, as appropriate, on ea

## Document text

(a) Each transport vehicle, freight container, portable tank, unit load device, or rail car that contains a poisonous material subject to the “Poison Inhalation Hazard” shipping description of § 172.203(m) must be placarded with a POISON INHALATION HAZARD or POISON GAS placard, as appropriate, on each side and each end, in addition to any other placard required for that material in § 172.504. Duplication of the POISON INHALATION HAZARD or POISON GAS placard is not required.

(b) In addition to the RADIOACTIVE placard which may be required by § 172.504(e), each transport vehicle, portable tank or freight container that contains 454 kg (1,001 pounds) or more gross weight of non-fissile, fissile-excepted, or fissile uranium hexafluoride must be placarded with a CORROSIVE placard and a POISON placard on each side and each end.

(c) Each transport vehicle, portable tank, freight container or unit load device that contains a material which has a subsidiary hazard of being dangerous when wet, as defined in § 173.124 of this subchapter, shall be placarded with DANGEROUS WHEN WET placards, on each side and each end, in addition to the placards required by § 172.504.

(d) Hazardous materials that possess secondary hazards may exhibit subsidiary placards that correspond to the placards described in this part, even when not required by this part (see also § 172.519(b) (4) of this subpart).

[Amdt. 172-123, 55 FR 52601, Dec. 21, 1990, as amended at 56 FR 66260, Dec. 20, 1991; 57 FR 45460, Oct. 1, 1992; Amdt. 172-127, 59 FR 49133, Sept. 26, 1994; Amdt. 172-151, 62 FR 1231, Jan. 8, 1997; 62 FR 39398, July 22, 1997; 65 FR 58626, Sept. 29, 2000; 72 FR 55692, Oct. 1, 2007; 79 FR 40610, July 11, 2014; 82 FR 15874, Mar. 30, 2017]

## Provenance

- Official: Yes
- Source: <https://www.ecfr.gov/on/2026-08-18/title-49/section-172.505>
- Source ID: `ecfr`
- SHA-256: `1f8932ceda0b0235d81d31f7bd2fbf6f72933659a69c7e82123fd3f6082f2f0f`
- Retrieved: 2026-08-20T05:45:59.130Z
- Exported: 2026-08-22T16:45:23.794Z
- Document slug: `49-cfr-172-505`

### Source metadata

```json
{
  "cfrTitle": 49,
  "part": "172",
  "section": "172.505",
  "subpart": "Subpart F—Placarding",
  "corpusVersion": "2026-08-18",
  "jurisdiction": "US"
}
```