Domestic Transport Using IMDG Code
Pipeline and Hazardous Materials Safety Administration · Aug 7, 2003 · Reference No. 03-0147
Interprets: 49 CFR § 176.27
Reggie’s quick take
A company asked whether hazardous materials may be shipped domestically under the International Maritime Dangerous Goods (IMDG) Code when all or part of the trip is by vessel. The agency said yes. Under § 171.12(b), material packaged, marked, classed, labeled, placarded, described, stowed, segregated and certified under the IMDG Code may be offered, accepted and transported within the United States if part of the trip is by vessel, subject to the listed conditions in paragraphs (b)(1)-(20). Materials that are not regulated under the HMR may move when described, marked and labeled per the IMDG Code. Materials forbidden under § 173.21 or Column 3 of the § 172.101 Table cannot move under this section.
Written by AI (Claude) on Oct 22, 2026. Robots make mistakes and leave things out, so the letter below is what counts. Not legal advice.
This responds to your June 16, 2003 letter and subsequent conversation with Mr. Darral Relerford regarding use of the International Maritime Dangerous Goods (IMDG) Code for domestic transportation under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). Specifically, you asked if the HMR allow hazardous materials to be shipped in accordance with the IMDG Code if all or part of the transportation is by vessel.
The answer is yes. Section 171.12(b) states that a material that is packaged, marked, classed, labeled, placarded, described, stowed and segregated, and certified in accordance with the IMDG Code, may be offered and accepted for transportation and transported within the United States if all or part of the transportation is by vessel. The conditions and limitations listed in paragraphs (b)(1)-(20) apply to such transportation.
Note that when a material is listed in the IMDG Code but is not regulated under the HMR, the material may be transported in the United States when described, marked and labeled in accordance with the IMDG Code. A material subject to the HMR that is not subject to the requirements of the IMDG Code or a material or package that is forbidden according to § 173.21 or Column 3 of § 172.101 Table may not be transported under § 171.12(b).
A letter of interpretation applies the regulations to the facts the requester described. It isn’t a regulation and isn’t legal advice. The agency’s copy.