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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 #21-0032R

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

Interpretation Response Details

Response Publish Date:

Company Name: Bettis Asphalt & Construction, Inc.

Individual Name: Cole Andersen

Location State: KS Country: US

View the Interpretation Document

Response text:

Cole Andersen
Bettis Asphalt & Construction, Inc.
PO Box 1694
Topeka, KS 66601

Reference No. 21-0032R

Dear Mr. Andersen:

This letter is in response to your March 22, 2021, letter requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the requirements for permanently mounted propane tanks for which the sole purpose is to power equipment mounted on the truck. You describe a scenario where a trailer is outfitted with commercial grade MC 331 propane fuel tanks to allow for hot in-place recycling for purposes of roadway asphalt repair. Specifically, you ask whether the transport vehicle is subject to the placarding requirements in Part 172, Subpart F of the HMR and the requirement for the driver to have a hazmat endorsement on the commercial driver's license (CDL).

In accordance with § 171.8, a fuel tank is a tank other than a cargo tank used to transport flammable or combustible liquid, or compressed gas for the purpose of supplying fuel for propulsion of the transport vehicle to which it is attached, or for the operation of other equipment on the transport vehicle.

Therefore, provided the permanently mounted propane tanks: 1) meet the requirements of 49 CFR 393.65 and 393.69 of the Federal Motor Carrier Safety Regulations (FMCSR) for fuel systems; 2) are used only for supplying fuel for the operation of the motor vehicle or its auxiliary equipment; and 3) are not marked as a DOT specification cargo tank, or meet the definition of a cargo tank in § 171.8, the mounted propane tanks are not subject to the HMR with respect to their use on the vehicle.

I hope this information is helpful. Please contact us if we can be of further assistance.


Dirk Der Kinderen
Chief, Standards Development Branch
Standards and Rulemaking Division

Regulation Sections

Section Subject
172.500 Applicability of placarding requirements