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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 #21-0016

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

Interpretation Response Details

Response Publish Date:

Company Name:

Individual Name: Amanda Davis

Location State: CA Country: US

View the Interpretation Document

Response text:

April 27, 2021

Amanda Davis
57475 CA-HWY 371 #1013
Anza, CA  92539

Reference No. 21-0016

Dear Ms. Davis:

This letter is in response to your February 17, 2021, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the classification of hemp flower and biomass. Specifically, you ask whether hemp is considered a hazardous material or hazardous substance in accordance with the HMR.

Section 173.22 states that it is the shipper's responsibility to classify a hazardous material properly. This Office does not generally perform this function. As provided in § 171.8, the term "hazardous material" includes hazardous substances, hazardous wastes, marine pollutants, elevated temperature materials, materials designated as hazardous in the Hazardous Materials Table (HMT; § 172.101), and materials that meet the defining criteria for hazard classes and divisions as specified in Part 173 of Subchapter C of the HMR. The hazard class is determined based on the chemical composition and hazard properties of the material as it is being offered for transportation. If a material does not meet the hazard class criteria in Part 173 and is not a hazardous substance, hazardous waste, or marine pollutant, then it is not subject to the HMR.

Hemp is not specifically defined in the HMR or listed in the HMT. Additionally, your incoming letter has not provided enough information about the properties of the hemp for this Office to confirm whether it constitutes a hazardous material. A determination as to whether hemp is subject to the HMR must be based on whether it meets the criteria in Part 173 to be considered a hazardous material. Dependent on the properties of the material as it is being offered for transportation, hemp may meet the criteria to be considered a hazardous material. For example, as a plant matter, hemp may pose self-heating hazards in accordance with Division 4.2, spontaneously combustible materials.

Therefore, it is recommended that you test the materials in accordance with the UN Manual of Tests and Criteria for appropriate classification. This determination should not be limited to consideration of Class 4.2, and all hazard classes should be considered in your determination of classification for your material.

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


T. Glenn Foster
Chief, Regulatory Review and Reinvention Branch
Standards and Rulemaking Division

171.8, 172.101, 173.22

Regulation Sections

Section Subject
171.8 Definitions and abbreviations
172.101 Purpose and use of hazardous materials table
173.22 Shipper's responsibility