# Class 9—Definitions.

**Citation:** 49 CFR 173.140  
**Type / status:** regulation / current  
**Agency:** Pipeline and Hazardous Materials Safety Administration  
**Effective:** 2026-08-18  
**Published:** Not stated

For the purposes of this subchapter, miscellaneous hazardous material (Class 9) means a material which presents a hazard during transportation but which does not meet the definition of any other hazard class. This class includes:

(a) Any material which has an anesthetic, noxious or other similar pr

## Document text

For the purposes of this subchapter, miscellaneous hazardous material (Class 9) means a material which presents a hazard during transportation but which does not meet the definition of any other hazard class. This class includes:

(a) Any material which has an anesthetic, noxious or other similar property which could cause extreme annoyance or discomfort to a flight crew member so as to prevent the correct performance of assigned duties; or

(b) Any material that meets the definition in § 171.8 of this subchapter for an elevated temperature material, a hazardous substance, a hazardous waste, or a marine pollutant.

[Amdt. 173-224, 57 FR 45463, Oct. 1, 1992, as amended by Amdt. 173-231, 57 FR 52939, Nov. 5, 1992; Amdt. 173-233, 58 FR 33305, June 16, 1993]

## Provenance

- Official: Yes
- Source: <https://www.ecfr.gov/on/2026-08-18/title-49/section-173.140>
- Source ID: `ecfr`
- SHA-256: `560541272470f516d069e35a296483634b22cba6ad24134a7db41bc947cc1fa4`
- Retrieved: 2026-08-20T05:46:04.092Z
- Exported: 2026-08-23T12:50:24.161Z
- Document slug: `49-cfr-173-140`

### Source metadata

```json
{
  "cfrTitle": 49,
  "part": "173",
  "section": "173.140",
  "subpart": "Subpart D—Definitions Classification, Packing Group Assignments and Exceptions for Hazardous Materials Other Than Class 1 and Class 7",
  "corpusVersion": "2026-08-18",
  "jurisdiction": "US"
}
```