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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 #09-0125 ([Association of American Railroads] [Mr. Robert E. Fronczak])

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

Interpretation Response Details

Response Publish Date:

Company Name: Association of American Railroads

Individual Name: Mr. Robert E. Fronczak

Location State: DC Country: US

View the Interpretation Document

Response text:

May 20, 2009





Mr. Robert E. Fronczak

Assistant Vice President

Environment and Hazardous Materials

Association of American Railroads

50 F Street NW

Washington, DC 20001-1564

Ref. No.: 09-0125

Dear Mr. Fronczak:

This responds to your April 27, 2009 email concerning the Association of American Railroad"s AAR-600 program. You note that the Tank Car Committee of the Association of American Railroads (AAR) has recommended discontinuance of the program and request that the Pipeline and Hazardous Materials Safety Administration (PHMSA) amend the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) to delete current requirements that reference AAR 600.

Currently, a bulk packaging, including a portable tank, transported in container-on-flatcar (COFC) or trailer-on-flatcar (TOFC) service must conform to the conditions specified in § 174.63 of the HMR. These regulations require approval by the Associate Administrator for Safety, Federal Railroad Administration, unless, among other things, the tank conforms to requirements in AAR-600 of the AAR Specifications for Tank Cars, "Specifications for Acceptability of Tank Containers." In accordance with AAR-600, approval and registration of compliant portable tanks is required, based on a determination that the tank meets all applicable standards and payment of a registration fee.

As your email notes, since incorporation of the AAR-600 standard into the HMR, PHMSA has adopted standards for portable tanks that meet or exceed the AAR-600 requirements. Moreover, most of the portable tanks listed in the AAR-600 standard are prohibited from new construction, although they may remain in service provided that they continue to meet the applicable standard. For these reasons, we agree that the § 174.63(c) reference to AAR-600 is outdated and should instead specify that portable tanks transported in COFC or TOFC service must conform to all HMR requirements applicable to portable tanks. We intend to propose a revision to § 174.63(c) as soon as practicable.

In the interim, until a revision can be effected through rulemaking, DOT will continue to require packagings outlined in §174.63 to meet the requirements of AAR-600. However, DOT will take no exception to AAR removing the registration requirement through publication of a circular as it has no substantial impact on the safe transportation of these shipments.

I hope this information is helpful. Please feel free to contact me if you have questions or need additional information.


Susan Gorsky

Regulations Officer

Office of Hazardous Materials Standards


Regulation Sections

Section Subject
174.63 Portable tanks, IM portable tanks, IBCs, Large Packagings, cargo tanks, and multi-unit tank car tanks