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 #10-0175 ([HQDA G-3/5/7 DAMO-SSD] [Mr. Steve Carey])

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

Interpretation Response Details

Response Publish Date:

Company Name: HQDA G-3/5/7 DAMO-SSD

Individual Name: Mr. Steve Carey

Location State: DC Country: US

View the Interpretation Document

Response text:

December 14, 2010



Mr. Steve Carey


400 Army Pentagon

Washington, D.C. 20310

Reference No. 10-0175

Dear Mr. Carey:

This responds to your letter requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the classification of a sample material with an unknown hazard. In your letter, you state that your organization is attempting to transport a sample of an unknown material suspected of containing a toxic material. You ask how the HMR apply to such a material being transported to an army laboratory for testing and analysis.

Section l72.10l(c)(11), states that except for certain materials, a shipper may assign a tentative shipping name, hazard class, and identification number to a material based on the shipper's knowledge of the material, the hazard precedence prescribed in § l73.2a, and defining hazard class criteria in Subchapter C. In this context, "tentative" means a temporary selection of a proper shipping name and hazard class used for a material until a more definite proper shipping name and hazard class can be assigned based on test data and analysis.

Exact physical and chemical properties of many materials may be unknown because concentrations of the components vary from shipment to shipment. Therefore, the use of a tentative classification and proper shipping name is authorized. However, should a shipper obtain more specific data on the properties of the material, the hazard class and proper shipping name must be modified, as applicable.

I hope this satisfies your inquiry. Please contact us if we can be of further assistance.


T. Glenn Foster

Chief, Regulatory Review and Reinvention Brach

Standards and Rulemaking Division

172.101, 173.2a

Regulation Sections

Section Subject
172.101 Purpose and use of hazardous materials table