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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 #12-0048 ([Boyle Transportation] [Mr. Enrique A. Araniz])

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

Interpretation Response Details

Response Publish Date:

Company Name: Boyle Transportation

Individual Name: Mr. Enrique A. Araniz

Location State: MA Country: US

View the Interpretation Document

Response text:

June 21, 2012



Mr. Enrique A. Araniz
Boyle Transportation
15 Riverhurst Road
Billerica, MA 01821

Ref. No. 12-0048

Dear Mr. Araniz:

This responds to your February 2, 2012 letter requesting clarification of applicability of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). In your letter, you indicate that it is your understanding that the temperature control units installed on your company"s trailers are not cargo heaters. Specifically, you request clarification whether your company"s temperature control units are excepted from the requirements of § 177.834(l)(1) when the trailers are used to transport Class 1 (explosive) material.

The answer is no. A motor vehicle equipped with a cargo heater of any type that is used for the transportation of Class 1 (explosive) material is subject to the conditions of § 177.834(l)(1). The temperature control unit on the trailer must be rendered inoperable by: 1) draining or removing the temperature control unit fuel tank; and 2) disconnecting the unit"s power source.

This interpretation is offered based on language from rulemakings under Docket No. HM-110 (copies enclosed). The rulemakings proposed that an explosive may not be loaded into the truck body or a trailer equipped with operable automatic temperature control equipment and that all automatic heating and refrigeration machinery must be rendered inoperative by disconnection of controls and power sources. This proposed language was subsequently revised to the current format in the HMR ("a cargo heater of any type"). The purpose of the revision was to clarify the requirements rather than to make a substantive change. Therefore, we conclude that a cargo heater as used in § 177.834(l)(1) includes a temperature control unit. We apologize for any confusion and note that Letter of Interpretation Ref. No. 06-0265 will be retracted.

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



Robert Benedict
Chief, Standards Development Branch
Standards and Rulemaking Division


Regulation Sections

Section Subject
177.834 General requirements