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 #11-0276 ([Mr. Lawrence W. Bierlein])

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

Interpretation Response Details

Response Publish Date:

Company Name:

Individual Name: Mr. Lawrence W. Bierlein

Location State: DC Country: US

View the Interpretation Document

Response text:

March 21, 2012


Mr. Lawrence W. Bierlein
1101 30th Street, NW
Suite 500
Washington, DC  20007

Reference No.: 11-0276

Dear Mr. Beirlein:

This responds to your letter requesting clarification of Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the shipment of 1.4S explosive devices.  In your letter, you describe a company that holds several 1.4S explosive device classifications issued as approvals in accordance with § 173.56.  Some of these approvals refer to the required packaging by Packing Instruction numbers specified in § 173.62, such as PI 142, while others specify the packaging directly on the face of the approval.  You note that § 173.61(e)(3) allows various 1.4S classification approvals (other than compatibility groups A or L), with proper inner and (if required) intermediate packaging to be shipped in the same required outer packaging, without having to test and seek separate classification approval for each mixed packaging.  You ask if several of these different 1.4S devices (not in compatibility groups A or L) may be shipped in the same outer packaging, under the provisions of § 173.61(e)(3)?

The answer is yes.  Section 173.61(e)(3) allows for 1.4S explosives to be packaged together with explosives of any other compatibility group except A or L, and the combined package may be treated as belonging to any of the package compatibility groups except S.  However, the shipper must ensure that the approved explosives are shipped in accordance with the prescribed combination packing instructions as required by each explosives approval.  This includes adhering to any specific packing instructions such as ensuring that explosives packagings requiring orientation arrows are packaged as prescribed.  Further, it is the opinion of this Office that § 173.61(e)(3) indicates an outer packaging is an overpack or outer packaging that contains the approved combination packaging which follows its individual specific packing instruction for each approved explosive.

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


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
173.61 Mixed packaging requirements