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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 #23-0074

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

Interpretation Response Details

Response Publish Date:

Company Name: Raytheon

Individual Name: Steven W. Steuer

Location State: AZ Country: US

View the Interpretation Document

Response text:

October 10, 2023

Steven W. Steuer
System Safety Engineer
1151 E Hermans Rd
Tucson, AZ  85706

Reference No. 23-0074

Dear Mr. Steuer:

This letter is in response to your August 7, 2023, email and subsequent email conversation requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) regarding the applicability of the HMR to expended explosive devices. Specifically, you ask what the appropriate classification is for an expended explosive device, such as an initiator that was originally approved for transportation as a Division 1.4 explosive.

The answer is that the classification of an expended explosive device must be determined case-by-case based on the presence or absence of energetic material remaining in the device. If the explosive substance within the device has been consumed/expended and there is no energetic substance remaining, then the device would not be subject to the requirements of the HMR for transportation as a Class 1 explosive material.

It is the responsibility of the shipper to determine whether the expended explosive device contains residual energetic material or any other chemical residue that may be subject to the HMR prior to offering the device for transportation. If a shipper plans to offer a device containing residual energetic materials—including a "dud" or misfired device—for transportation, they must seek a competent authority approval in accordance with § 173.56.

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


Regulation Sections

Section Subject
173.56 New explosives-definition and procedures for classification and approval