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Interpretation Response #18-0052

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

Interpretation Response Details

Response Publish Date:

Company Name: Texas Highway Patrol Division

Individual Name: Sergeant Brad Gibson

Location State: TX Country: US

View the Interpretation Document

Response text:


August 20, 2018

Sergeant Brad Gibson
Texas Highway Patrol Division
Commercial Vehicle Enforcement Training Unit
6200 Guadalupe St., Bldg. P
Austin, TX  78752

Reference No. 18-0052

Dear Sergeant Gibson:

This letter is in response to your April 2, 2018, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the selection of a proper shipping name.  Specifically, you ask whether the optional, italicized text of a proper shipping name shown in the § 172.101 Hazardous Materials Table (HMT) may be modified.  In your email, you provide an example of the following description and ask whether the word substance in the optional text may be modified to read material.

UN1942, Ammonium nitrate, with not more than 0.2% combustible substances [materials], including any organic substance [material] calculated as carbon, to the exclusion of any other added substance [material] 

The answer is no.  Although the text in italics is not part of the proper shipping name and its use is optional, unless stated otherwise (e.g., actual concentrations in § 172.101(c)(6)), any modification of the shipping description, to include optional text, is not permitted.  As prescribed in § 172.101(l)(2), any alteration of a shipping description or associated entry which is listed in the § 172.101 HMT must receive prior written approval from the Associate Administrator. 

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

172.101, 172.101(l)(2), 172.101(c)(6)),


Regulation Sections

Section Subject
172.101 Purpose and use of hazardous materials table