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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 #07-0037 ([Horizon Lines] [Mr. Cliff Bartley ])

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

Interpretation Response Details

Response Publish Date:

Company Name: Horizon Lines

Individual Name: Mr. Cliff Bartley 

Location State: FL Country: US

View the Interpretation Document

Response text:

Jun 28, 2007


Mr. Cliff Bartley                 Reference No. 07-0037

Horizon Lines

Blount Island

5800-1 William Mills Street

Jacksonville, FL 32226

Dear Mr. Bartley:

This responds to your February 1, 2007, letter regarding requirements under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) as they apply to hazardous cargo moving in refrigerated/heated cargo containers (reefers) in the Alaska trade during the winter months.

You state that heating hazardous cargo is sometimes necessary to avoid freeze damage to items such as Class 3 (flammable) paints and other common hazardous cargo shipments that would not normally require temperature control during the warmer parts of the year in the Alaska market. These products can be damaged and rendered useless if subjected to the freezing weather during the winter months. A reefer is required to provide heat to avoid cargo damage. You ask if a standard refrigerated container operating in the heat mode may be used to transport hazardous cargo that requires temperature control for quality during the winter months.

Section 177.834(1) establishes conditions for the use of cargo heaters when transporting certain hazardous materials by motor carrier. Paragraph (l)(2)(iii) of this section sets forth restrictions for the use of automatic cargo-space-heating temperature control devices. Such a device may be used when transporting Class 3 or Division 2.1 materials only if the conditions in paragraph (l)(2)(iii)(A) of § 177.834 are met: (1) the electrical apparatus in the cargo compartment must be non-sparking or explosion proof (2) there must be no combustion apparatus in the cargo compartment; (3) there must be no connection for return of air from the cargo compartment to the combustion apparatus; and (4) the heating system may not heat any part of the cargo to more than 54° C (129° F). In addition, the automatic cargo-space-heating temperature control device must conform to heater requirements in 49 CFR 393.77.

In accordance with § 176.76(d), a transport vehicle or freight container equipped with heating or refrigeration equipment may be operated on board a vessel. However, the equipment may not he operated in any hold or compartment containing a flammable liquid or gas unless it is designed to operate within an environment containing flammable vapors.

If the temperature-control equipment you utilize does not conform to the requirements specified in the HMR, you may need to apply for a special permit under the procedures prescribed in 49 CFR 107.105.

I hope this information is helpful. If we can be of further assistance, please contact us.



John A. Gale

Chief, Standards Division

Office of Hazardous Materials Standards

173.21, 176.76 (d), 177.834

Regulation Sections

Section Subject
173.21 Forbidden materials and packages
176.76 Transport vehicles, freight containers, and portable tanks containing hazardous materials
177.834 General requirements