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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 #21-0017

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

Interpretation Response Details

Response Publish Date:

Company Name: The Sulphur Institute

Individual Name: Craig Jorgenson

Location State: DC Country: US

View the Interpretation Document

Response text:

June 17, 2021

Mr. Craig Jorgenson
The Sulphur Institute
1020 19th Street NW, Suite 895
Washington, DC  20036

Reference No. 21-0017

Dear Mr. Jorgenson:

This letter is in response to your February 23, 2021, letter requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the transportation of sulfur by rail. Specifically, you ask whether a material classified as "NA1350, Sulfur, 9, PG III" that meets the requirements in Special Provision 30 (e.g., formed to a specific shape) in § 172.102 of the HMR is required to use a bulk packaging listed in § 173.240, as directed in Column 8C of the § 172.101 Hazardous Materials Table (HMT). You interpret that under § 173.240 a sift-proof non-DOT Specification closed car (i.e., a closed rail car) must be used. Further, you believe that there is a gap between Special Provision 30 of the HMR and Special Provision (SP) 33 of Transport Canada’s Transportation of Dangerous Goods Regulations (TDG Regulations).

The answer is no. In accordance with Special Provision 30—which is assigned to both "NA1350, Sulfur, 9, PG III" and "UN1350, Sulfur, 4.1, PG III"—sulfur is not subject to the requirements of the HMR if transported in a non-bulk packaging or if formed to a specific shape (e.g., prills, granules, pellets, pastilles, or flakes). Also note that a non-bulk packaging is defined in § 171.8 and means, in part, a packaging which has a maximum net mass of 400 kg (882 pounds) or less and a maximum capacity of 450 L (119 gallons) or less as a receptacle for a solid.

Therefore, Special Provision 30 is consistent with SP 33 of the TDG Regulations, which states the regulations do not apply to sulfur in a quantity less than or equal to 400 kg per means of containment or have been formed to a specific shape such as prills, granules, pellets, pastilles or flakes.

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

171.8, 172.101, 172.102, 173.240

Regulation Sections

Section Subject
171.8 Definitions and abbreviations
172.101 Purpose and use of hazardous materials table
172.102 Special provisions
173.240 Bulk packaging for certain low hazard solid materials