49 CFR § 173.338 - Tungsten hexafluoride.

---
identifier: "/us/cfr/t49/s173.338"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "49 CFR § 173.338 - Tungsten hexafluoride."
title_number: 49
title_name: "Transportation"
section_number: "173.338"
section_name: "Tungsten hexafluoride."
chapter_name: "PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
subchapter_number: "C"
subchapter_name: "HAZARDOUS MATERIALS REGULATIONS"
part_number: "173"
part_name: "SHIPPERS—GENERAL REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "49 U.S.C. 5101-5128, 44701; 49 CFR 1.81, 1.96 and 1.97."
cfr_part: "173"
---


# 173.338 Tungsten hexafluoride.

(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]