USA Banner

Official US Government Icon

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure Site Icon

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Interpretation Response #22-0047

Below is the interpretation response detail and a list of regulations sections applicable to this response.

Interpretation Response Details

Response Publish Date:

Company Name: Bureau Veritas Inspection and Insurance Company

Individual Name: Edgar A. Whittle

Location State: MA Country: US

View the Interpretation Document

Response text:

April 3, 2023

Edgar A. Whittle
Director, Codes & Standards
Bureau Veritas Inspection and Insurance Company
330 Lynnway, Suite 403
Lynn, MA  01901

Reference No. 22-0047

Dear Mr. Whittle:

This letter is in response to your April 21, 2022, letter requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to foreign manufactured United Nations (UN) pressure receptacles. Specifically—with respect to § 173.24(d)(2) regarding UN standard packagings manufactured outside the U.S.—you ask whether a manufacturer of UN pressure receptacles (i.e., cylinders) in a foreign country that follows national or international regulations based on the UN Recommendations on the Transport of Dangerous Goods (UN Recommendations) and that fully conforms to applicable provisions in the UN Model Regulations and the requirements of the HMR, including reuse provisions, can export the cylinders to the U.S. without having the cylinders be inspected by an Independent Inspection Agency (IIA) approved by the Pipeline and Hazardous Materials Safety Administration (PHMSA) Associate Administrator for Hazardous Materials Safety (Associate Administrator).

The answer is no. Except as provided in § 171.23(a)(3)-(5), UN cylinders must be marked "USA" or "CAN" as country of approval for transportation to, from, and within the United States (see § 171.23(a)(2)(iv)). Sections 178.69 through 178.71 contain the requirements applicable to UN cylinders marked “USA” as country of approval. For "USA" marked UN cylinders, these requirements include approval from the Associate Administrator for the manufacturer's quality system (see § 178.69(a)(1)), IIA design type review and design type approval issued by the Associate Administrator (see § 178.69(b)), and use of a production IIA—approved by the Associate Administrator—to witness inspections and tests during manufacture (see § 178.70(e)).

Please note that if the UN cylinders in question meet one of the following exceptions provided in § 171.23(a)(3)-(5), then the "USA" mark and use of an approved IIA is not required:

  • Pi-marked cylinders for import or export (see § 171.23(a)(3));
  • Cylinders imported for discharge in a single port area (see § 171.23(a)(4)); or
  • Cylinders filled for export or for use on board a vessel (see § 171.23(a)(5)).

I hope this information is helpful. Please contact us if we can be of further assistance.


Dirk Der Kinderen
Chief, Standards Development Branch
Standards and Rulemaking Division

171.23(a)(2)(iv), 171.23(a)(3)-(5), 178.69(a)(1), 178.69(b), 178.70(e)

Regulation Sections

Section Subject
171.23 Requirements for specific materials and packagings transported under the ICAO Technical Instructions, IMDG Code, Transport Canada TDG Regulations, or the IAEA Regulations
178.69 Responsibilities and requirements for manufacturers of UN pressure receptacles
178.70 Approval of UN pressure receptacles