# Tungsten hexafluoride.

**Citation:** 49 CFR 173.338  
**Type / status:** regulation / current  
**Agency:** Pipeline and Hazardous Materials Safety Administration  
**Effective:** 2026-08-18  
**Published:** Not stated

(a) Tungsten hexafluoride must be packaged in specification 3A, 3AA, 3BN, or 3E (§§ 178.36, 178.37, 178.39, 178.42 of this subchapter) cylinders. Cylinders must be equipped with a valve protection cap or be packed in a strong outer packaging meeting the provisions of § 173.40. Outlets of any valves 

## Document text

(a) Tungsten hexafluoride must be packaged in specification 3A, 3AA, 3BN, or 3E (§§ 178.36, 178.37, 178.39, 178.42 of this subchapter) cylinders. Cylinders must be equipped with a valve protection cap or be packed in a strong outer packaging meeting the provisions of § 173.40. Outlets of any valves must be capped or plugged. As an alternative, the cylinder opening may be closed by the use of a metal plug. Specification 3E cylinders must be shipped in an overpack that meets the provisions of § 173.40.

(b) In place of the volumetric expansion test, DOT 3BN cylinders used in exclusive service may be given a complete external visual inspection in conformance with part 180, subpart C, of this subchapter, at the time such periodic requalification becomes due. Cylinders that undergo a complete external visual inspection, in place of the volumetric expansion test, must be condemned if removed from tungsten hexafluoride service.

[74 FR 16143, Apr. 9, 2009, as amended at 75 FR 5395, Feb. 2, 2010]

## Provenance

- Official: Yes
- Source: <https://www.ecfr.gov/on/2026-08-18/title-49/section-173.338>
- Source ID: `ecfr`
- SHA-256: `cc213c3f4af554aa493e720387982138f8c85dfe694559603a263fc1dfddb1b2`
- Retrieved: 2026-08-20T05:46:04.092Z
- Exported: 2026-08-22T04:09:08.055Z
- Document slug: `49-cfr-173-338`

### Source metadata

```json
{
  "cfrTitle": 49,
  "part": "173",
  "section": "173.338",
  "subpart": "Subpart G—Gases; Preparation and Packaging",
  "corpusVersion": "2026-08-18",
  "jurisdiction": "US"
}
```