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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 #22-0139

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

Interpretation Response Details

Response Publish Date:

Company Name: WM Pacific Northwest

Individual Name: Haydon Morris

Location State: WA Country: US

View the Interpretation Document

Response text:

August 24, 2023

Haydon Morris
Transportation & Logistics Manager
WM Pacific Northwest
18905 176th Ave NE
Woodinville, WA  98072

Reference No. 22-0139

Dear Mr. Morris:

This letter is in response to your December 19, 2022, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) regarding the requirements for visibility and display of placards on "half high" intermodal containers loaded with hazardous waste that move on "well cars" by rail. Specifically, you ask whether—in the event that "half high" (5-ft. tall) intermodal container placards are not visible when placed in a "well car"—does the well car itself need to be placarded on all four sides.

The answer is yes. Generally, in accordance with § 172.504(a), each bulk packaging, freight container, unit load device, transport vehicle, or rail car containing any quantity of a hazardous material must be placarded on each side and each end. For rail transportation, § 172.508(a) allows placards displayed on a transport container to satisfy the requirements for affixing placards on a rail car. However, in this scenario, the placards on the "half high" intermodal containers in the rail car (i.e., well car) will not be visible and therefore, both the intermodal containers and the rail cars must be placarded.

Furthermore, § 172.516(a) states that each placard on a rail car must be clearly visible from the direction it faces, except from the direction of another rail car to which the rail car is coupled. Therefore, in a scenario such as this where the "half high" intermodal container placards are not visible when placed in a well car, the well car placards must be displayed so that they are clearly visible from the direction it faces—except from the direction of another rail car to which it is coupled.

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

172.504(a), 172.508(a), 172.516(a)

Regulation Sections

Section Subject
172.504 General placarding requirements
172.508 Placarding and affixing placards: Rail
172.516 Visibility and display of placards