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 #17-0078

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

Interpretation Response Details

Response Publish Date:

Company Name: UL Supply Chain & Sustainability

Individual Name: Kevin Skerrett

Location State: NY Country: US

View the Interpretation Document

Response text:

May 13, 2019

Mr. Kevin Skerrett
UL Supply Chain & Sustainability
Senior Regulatory Specialist
23 British American Boulevard
Latham, NY  12110

Reference No. 17-0078

Dear Mr. Skerrett:

This letter is in response to your August 2, 2017, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the shipment of marine pollutants identified as solutions. We apologize for the delay in responding and any inconvenience this may have caused.

We have paraphrased and answered your questions as follows:

Q1. You note that "hypochlorite solutions" was added to Appendix B of the § 172.101 Hazardous Materials Table (HMT) in the HM-215N final rule, published March 30, 2017 [82 FR 15796]. You further note that the definition of "marine pollutant" in § 171.8 contains criteria to use if there is a solution or mixture of one or more listed marine pollutants. Therefore, you ask if the 10% by weight marine pollutant and 1% by weight severe marine pollutant criteria for mixtures and solutions applies to "hypochlorite solutions" since the name is listed as a solution.

A1. The answer is no.  The 10% by weight marine pollutant and 1% by weight severe marine pollutant criteria for mixtures and solutions in the definition of "marine pollutant" in § 171.8 do not apply to "hypochlorite solutions." The addition of "hypochlorite solutions" to Appendix B in HM-215N harmonized the HMR with the addition of "P" to the International Maritime Dangerous Goods (IMDG) Code for UN1791, which covers all concentrations of "hypochlorite solutions" that meet the classification criteria for Class 8. The International Maritime Organization classified these solutions as marine pollutants based on the recommendation of the Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection (GESAMP) after evaluating the available aquatic toxicity data.  For reference, please see the GESAMP Hazard Evaluation of Substances Transported by Ships (BLG.1/Circ.35).

Q2. You ask if Answer A1 should be considered a general rule for addressing other solution entries in Appendix B of the § 172.101 HMT (e.g., "Copper chloride solution," "Cyanide solutions," and "Zinc chloride solution") and the applicability of marine pollutant requirements.

A2. The answer is yes.

Q3. You note that Answers A1 and A2 apply only to domestic U.S. shipments and that international shipment is controlled by the provisions in 2.10 of the IMDG Code. You ask if any material identified as "UN1791, Hypochlorite solution" must be considered a marine pollutant under the IMDG Code.

A3. The answer is yes. A "P" is shown in column 4 of the IMDG Code Dangerous Goods list for the entries for "UN1791, Hypochlorite solution." This indicates that solutions meeting the classification criteria of this UN identification number are known marine pollutants.

Q4. In the event data is available to show that a diluted solution classified as "UN1791, Hypochlorite solution" no longer meets the marine pollutant criteria in 2.9.3 of the IMDG Code, you ask if a Competent Authority Approval Document from PHMSA is required to remove the marine pollutant designation for international shipment, or if a shipper could make this determination without such an approval.

A4. If a material is identified as a marine pollutant in the IMDG Code, but does not meet the criteria for a marine pollutant in sections and, it may be excepted from the applicable marine pollutant requirements if approved by the Associate Administrator (see of the IMDG Code).

I hope this information is helpful. If you need additional assistance, please contact the Standards and Rulemaking Division at (202) 366-8553.


Shane C. Kelley
Standards and Rulemaking Division

171.8, 172.101

Regulation Sections

Section Subject
171.8 Definitions and abbreviations
172.101 Purpose and use of hazardous materials table