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

Interpretation Response #18-0046

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

Interpretation Response Details

Response Publish Date:

Company Name: Hawks Logistics

Individual Name: Steve Hawks

Location State: OK Country: US

View the Interpretation Document

Response text:

October 11, 2018

Steve Hawks
Hawks Logistics
1120 Bank Side Circle
Edmond, OK 73012

Reference No. 18-0046

Dear Mr. Hawks:

This letter is in response to your March 23, 2018, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to Special Provision (SP) 387 for substances requiring stabilization prior to transportation.

We have paraphrased and answered your questions as follows:
Q1. You ask whether the carrier may rely on the shipper to ensure that the stabilized material will be such that the material will not become unstable at temperatures of 50 °C (122 °F) or less.
A1. The answer is yes.  In accordance with § of the HMR, it is the responsibility of the shipper, or “person who offers,” to properly classify and describe a hazardous material, as well as to determine whether the packaging or container is authorized for the hazardous material that is being offered for transportation.
Q2. You ask whether a carrier may rely on information provided on a material’s Safety Data Sheet (SDS) that states a hazardous material does not require temperature stabilization while in transportation.
A2. An SDS may be a useful reference document for information pertaining to a hazardous material; however, PHMSA does not verify or certify transportation information provided in an SDS.  Therefore, an SDS may not reflect all requirements of, or exceptions from, the HMR—in your case, SP 387 and § 173.21(f).  However, § 173.22 of the HMR places primary responsibility on the shipper, or “person who offers,” to properly classify, communicate the hazard of a hazardous material, and determine that the packaging is authorized for the hazardous material.  Pursuant to § 171.2(f) of the HMR, a carrier may rely on information provided by the shipper, unless the carrier knows that the information provided is incorrect.

Q3. You ask whether the HMR require the shipper to provide the self-accelerated polymerization temperature (SAPT) or self-accelerated decomposition temperature (SADT) for self-reactive materials.
A3. The answer no.  SAPT and SADT values are defining characteristics used for the classification of certain Division 4.1 hazardous materials.  However, the HMR currently do not require that the shipper provide that information to the carrier or on a shipping paper for transportation.

Q4.  You ask why there is a sunset date on the provisions added in SP 387.

A4. PHMSA included a “sunset” provision of January 2, 2019, for all amendments concerning polymerizing substances.  PHMSA intends to review and research the implications of the polymerizing substance amendments and readdress the issue in the next international harmonization rulemaking.  The HM-215N Harmonization With International Standards (RRR) Final Rule (82 FR 15796; March 30, 2017) further discusses PHMSA’s decision to include a sunset date.  The final rule may be accessed online at:

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

173.22, 173.21(f), 171.2(f)














Regulation Sections

Section Subject
171.2 General requirements
173.21 Forbidden materials and packages
173.22 Shipper's responsibility