Interpretation Response #26-0082
Below is the interpretation response detail and a list of regulations sections applicable to this response.
Interpretation Response Details
Response Publish Date:
Company Name: UPL NA, Inc.
Individual Name: Lori A. DiRe
Location State: NC Country: US
View the Interpretation Document
Response text:
October 6, 2026
Lori A. DiRe
Regulatory Compliance and Product Safety Specialist
UPL NA, Inc.
5 Laboratory Drive
Building 1, Suite 1000
Durham, NC 27009
Reference No. 26-0082
Dear Ms. DiRe:
This letter is in response to your June 17, 2026 email, and subsequent phone conversation with my staff, requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to marine pollutants. Specifically, you ask whether supplemental explanatory wording can be added to the exterior of a package marked in accordance with the International Maritime Dangerous Goods (IMDG) Code, to clarify that a product is not regulated by ground transport in the United States. In addition, you ask whether the provisions of § 171.4(c) extend to international regulatory markings only, or to supplemental wording as well.
PHMSA previously issued a letter of interpretation, which clarified that it is permissible to transport marine pollutants by domestic ground transportation with IMDG Code markings and labels, despite the regulations excepting them from the marking requirements. The letter clarifies that explanatory wording would not be a violation of prohibited marking provisions (See § 172.401(c)(1)).
Therefore, the explanatory wording provided in your request is permissible. In addition, the HMR do not prohibit additional narrative indications like the example provided in your request as long as, if applicable, they are placed so as not to reduce the effectiveness of
markings required by the HMR (see § 172.304(a)(4)).
I hope this information is helpful. Please contact us if we can be of further assistance.
Sincerely,
Alexander Wolcott
Acting Chief, Regulatory Review & Reinvention
Standards and Rulemaking Division
171.4(c) 172.304(a)(4) 172.401(c)(1)
Regulation Sections
| Section | Subject |
|---|---|
| 171.4 | Marine pollutants |
| 172.304 | Marking requirements |
| 172.401 | Prohibited labeling |