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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 #98-0376 ([Pratt & Whitney] [Ms. Jenny Hobby])

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

Interpretation Response Details

Response Publish Date:

Company Name: Pratt & Whitney

Individual Name: Ms. Jenny Hobby

Location State: CA Country: US

View the Interpretation Document

Response text:

JAN 13, 1999


Ms. Jenny Hobby                          Ref. No. 98-0376
Pratt & Whitney
Traffic Packaging Engineering
600 Metcalf Road
San Jose, CA 95138

Dear Ms. Hobby:

This is in response to your letter of December 11, 1998 concerning the segregation of explosives under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180).  Specifically you were inquiring about the rules for transporting Division 1.4B and 1.2B explosives with Division 1.4S detonators.

Section 177.848 contains the Compatibility Table for Class 1 (Explosive) materials.  Note four is indicated when considering Group B and S materials which refers to § 177.835. Section 177.835(q) prohibits the transportation of detonators on the same motor vehicle with any Division 1.1, 1.2, or 1.3 (Class A or Class B) material (except other detonator assemblies, boosters with detonators or other detonators), explosives for blasting, or detonating cord Division 1.4 (Class C) material.  These materials may be transported on the same motor vehicle only if the requirements of § 177.835(g)(1), (2), and (3) are met.

We also wish to clarify the difference between a transport vehicle and a motor vehicle, as this issue was raised in telephone conversations with members of our staff.  As defined in  171.8, a transport vehicle means a cargo-carrying vehicle and each cargo-carrying body is a separate transport vehicle.

A motor vehicle is defined as any number of transport vehicles powered by the same motor or engine (except vehicles which travel by rail or a trolley).

I hope this satisfies your request.



John A. Gale
Transportation Regulations Specialist
Office of Hazardous Materials Standards


Regulation Sections

Section Subject
177.835 Class 1 materials