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Interpretation Response #12-0198 ([Pacific Scientific Energetic Materials Company] [Mr. Timothy S. Dillon])

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

Interpretation Response Details

Response Publish Date:

Company Name: Pacific Scientific Energetic Materials Company

Individual Name: Mr. Timothy S. Dillon

Location State: CA Country: US

View the Interpretation Document

Response text:

December 13, 2012


Mr. Timothy S. Dillon
Environmental Health and Safety Manager
Valencia Advanced Technology Center
Pacific Scientific Energetic Materials Company
24908 Avenue Kearny
Valencia, CA 91355

Reference No. 12-0198

Dear Mr. Dillon:

This is in response to your September 5, 2012 letter requesting clarification of the requirements for explosive testing "by analogy" under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). In your letter, you state the explosive articles for which you request this relief are in three categories: 1) they have the same part but different part numbers on two or more articles in the device due to customer requirements, such as a dash number or letter designation; 2) they have similar parts with the same energetic material and article function, including a mechanical change from the first article, such as a change in thread size or a different connector; or 3) they have similar parts with similar functions but the upper level assemblies of the devices are different, e.g., airplane versus helicopter/missile versus rocket, with the same or less net explosive weight and different part number.

You ask if your clients may use test laboratories other than the original laboratory that performed the test when: 1) the original laboratory is unable to meet the delivery schedule established by your company and your customer, or 2) the original laboratory is unable to meet the quality and supply chain requirements as a vendor approved by your company"s Department of Defense customers.

The answer is no. The Pipeline and Hazardous Materials Safety Administration (PHMSA) permits an explosive to be classified "by analogy" only by the laboratory that performed the original classification tests on the material. PHMSA does not permit another laboratory to review test work it did not perform on an explosive material and draw classification analogies for this material after the explosive or the device in which it is placed have been altered.

I hope this satisfies your request.



T. Glenn Foster
Chief, Regulatory Review and Reinvention Branch
Standards and Rulemaking Division


Regulation Sections

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