You are here

Interpretation Response #06-0265

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

Interpretation Response Details

Response Publish Date: 07-13-2007
Company Name: Hissong Kenworth-GMC, Inc.    Individual Name: Mr. Jeff Reutter
Location state: OH    Country: US

View the Interpretation Document

Response text:

Jul 13, 2007



Mr. Jeff Reutter
Manager - Sales Administration/Marketing
Hissong Kenworth-GMC, Inc.
2890 Brecksville Rd.
P.O. Box 457
Richfield, OH 44286

Reference No. 06-0265

Dear Mr. Reutter:

This responds to your November 27, 2006 letter requesting clarification on what constitutes a "cargo heater" under § 177.834(l)(1) of the Hazardous Materials Regulations (49 CFR Parts 171-180).

According to your letter, your question relates to a diesel powered mechanical refrigeration unit installed on an insulated van body mounted on a truck chassis. The refrigeration unit is a split condenser/evaporator design with the diesel engine and condenser installed on the exterior and the evaporator installed on the interior of the insulated van body. System capabilities can maintain temperatures inside the insulated van body from -20 degrees to +85 degrees Fahrenheit. The refrigeration unit uses the truck chassis fuel tanks for its fuel source. There are in-cab controls to monitor and adjust temperature inside the insulated van body or to activate or inactivate the refrigeration unit. You ask if a mechanical refrigeration unit as described constitutes a "cargo heater."

Section 177.834(l)(1) states that when transporting Class 1 (explosive) materials, a motor vehicle equipped with a cargo heater of any type may transport Class 1 (explosive) materials only if the cargo heater is rendered inoperable by: (i) draining or removing the cargo heater fuel tank; and (ii) disconnecting the heater"s power source. Based on your description and supporting product specifications and photograph, it is the opinion of this Office that your mechanical refrigeration unit does not constitute a "cargo heater" as that term is used in § 177.8 34(l)(1) of the HMR.

I hope this answers your inquiry.


John A. Gale
Chief, Standards Development
Office of Hazardous Materials Standards

177.834 (1)

Regulation Sections

Section Subject
§ 177.834 General requirements