• Placarding requirements, placement, and exceptions vary according to the category of the material being transported and the type of packaging containing the material.

Hazardous materials placards correspond very closely with the shape, color and design of the hazardous materials warning labels. However, placards are much larger than labels. Placards alert persons to the potential dangers associated with the particular hazardous material contained in a motor vehicle, rail car, freight container, cargo tank, or portable tank.

The placarding requirements apply to each person who offers for transport or transports hazardous materials. The placarding requirements do not apply to the following materials:

• Infectious substances (Division 6.2).
• Materials classed as Other Regulated Material (ORM-D).
• Materials authorized to be transported as a limited quantity (when properly identified on the shipping papers or marked in accordance with 172.315).
• Materials packaged as “small quantities” (under the provisions of 173.4, 173.4a, or 173.4b).
• Materials prepared in accordance with 173.13 (Exceptions for Classes 3, 8, 9, and Division 4.1, 4.2, 4.3, 5.1, 6.1).
• Combustible liquids in non-bulk packagings. (172.500)

Placards are used to identify the hazard or hazards of materials contained in bulk packagings, freight containers, unit load devices, transport vehicles, or rail cars.

The responsibility for affixing or supplying placards varies according to the mode of transport and the type of packaging used to transport the hazardous material.

Placarding tables

Placarding requirements, placement, and exceptions vary according to the category of the material (hazard class, division, packing group or description) being transported and the type of packaging (bulk or non-bulk) containing the material. Each bulk packaging, freight container, unit load device, transport vehicle, or rail car containing hazardous material must be placarded on each side and each end (with some exceptions) with the type of placards specified in Table 1 or Table 2 of 172.504.

To determine what placards are required, a facility must know:

• The type of packaging (bulk or non-bulk) containing the hazardous material(s).
• The hazard category (class, division, packing group, or description) and subsidiary hazard(s) of the hazardous material(s) present.
• The weight of non-bulk packages in each hazard category.

The most dangerous categories of hazardous materials are located in Table 1. Any quantity of material falling within the categories listed in Table 1 must be placarded.