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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 #21-0059

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

Interpretation Response Details

Response Publish Date:

Company Name: XPO Logistics

Individual Name: Ms. Marie Copeman

Location State: MI Country: US

View the Interpretation Document

Response text:

February 3, 2022

Ms. Marie Copeman
XPO Logistics
2211 Old Earhart Road
Ann Arbor, MI  48105

Reference No. 21-0059

Dear Ms. Copeman:

This letter is in response to your May 25, 2021, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to placarding. In your email, you describe a scenario where a vehicle is placarded on four sides—two sides with rail combustible liquid placards and two sides with standard combustible liquid placards. You ask whether it is permissible to placard a vehicle using both the rail combustible liquid placards as described in § 172.332(c)(4) and the standard combustible liquid placards as described in § 172.544, at the same time.

The answer is yes. As you noted in your email, § 172.332(c)(4) states "For a COMBUSTIBLE placard used to display an identification number, the entire background below the white background for the identification number must be white during transportation by rail and may be white during transportation by highway." Although not specified, there is no prohibition in the HMR from using a combination of the two authorized combustible liquid placards on the same motor vehicle by highway transportation. Therefore, it is the opinion of this Office that using both placards on the same motor vehicle is permitted under the HMR only during highway transportation.

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


T. Glenn Foster
Chief, Regulatory Review and Reinvention Branch
Standards and Rulemaking Division

172.332(c)(4), 172.544

Regulation Sections

Section Subject
172.332 Identification number markings
172.544 COMBUSTIBLE placard