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Interpretation Response #10-0087 ([US Dynamics Corporation] [Mr. George Jantzen])

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

Interpretation Response Details

Response Publish Date:

Company Name: US Dynamics Corporation

Individual Name: Mr. George Jantzen

Location State: NY Country: US

View the Interpretation Document

Response text:

May 28, 2010





Mr. George Jantzen

US Dynamics Corporation

425 Bayview Avenue

Amityville, New York 11758

Ref. No. 10-0087

Dear Mr. Jantzen:

This responds to your April 9, 2010 letter requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). You state that your company purchases a small explosive device from your supplier. It comes with the suppliers approval number (i.e., EX-number). Your company then installs the unaltered part into a gyroscope prior to shipment. Specifically, you ask if you must apply for a separate explosive approval number (i.e., EX-number) for the assembled gyroscope even though you have not altered the explosive component in any way.

The answer is yes. By installing a previously approved explosive device into a new article, you have altered the design. As a result, the proper shipping name and class may no longer be appropriate, depending on how the explosive device is installed, the overall size and the packaging. Thus, the article is a new explosive as defined in § 173.56(a) and must be examined, classed, and approved in accordance with § 173.56.

I hope this information is helpful. If you have further questions, please contact this office.


Charles E. Betts

Chief, Standards Development

Office of Hazardous Materials Standards


Regulation Sections

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