Placards are used to graphically communicate a hazard of a material being transported. A placard often contains the hazardous material’s identification (ID) number, which is the number assigned to the proper shipping name of the material being transported.

General Specification for Placards

Placards may be made of plastic, metal, or any other durable materials capable of withstanding a 30-day exposure to open weather without significant deterioration or substantial reduction in effectiveness. Reflective or retroreflective material may be used on placards if prescribed colors, strength, and durability are maintained.

Design. The printing, inner border, and symbol on each placard must be as shown in 49 CFR 172.521 to 172.560. Although the dotted line border shown on each placard is not part of the placard specification, a dotted or solid line outer border may be used when needed to indicate the full size of a placard that is part of a larger format or is on a background of a noncontrasting color. Text indicating the hazard is not required on the placard, except for Class 7 and the DANGEROUS placard. The background color, symbol, text, numerals, and inner border on a placard must be as specified in 49 CFR 172.521 to 172.558.

Size. The placard size specifications were made consistent with the UN Model Regulations and are as follows: Each diamond (square on point) placard must measure at least 250 millimeters (mm) (9.84 inches (in.)) on each side and must have a solid-line inner border approximately 12.5 mm inside and parallel to the edge. The 12.5-mm measurement is from the outside edge of the placard to the outside of the solid line forming the inner border.

Affixing Placards

Each person offering a hazardous material for transportation by highway must provide the transporter with the required placards for the material before or at the same time the material is offered for transportation, unless the transporter’s motor vehicle is already placarded for the material. A motor carrier is prohibited from transporting hazardous material unless the required placards are affixed to the vehicle.

Bulk packaging. Each bulk packaging (e.g., cargo tank trucks and intermediate bulk containers (IBCs)) that is required to be placarded when it contains a hazardous material must remain placarded when it is emptied, unless it:

• Is sufficiently cleaned of residue and purged of vapors to remove any potential hazard;
• Is refilled, with a material requiring different placards or no placards, to such an extent that any residue remaining in the packaging is no longer hazardous; or
• Contains the residue of a hazardous substance in Class 9 in a quantity less than the reportable quantity and conforms to the requirements for empty packagings.

Visibility and Display

Each placard on a motor vehicle and railcar must be clearly visible from the direction it faces, except from the direction of another transport vehicle or railcar to which the motor vehicle or railcar is coupled. Required placarding of the front of a motor vehicle may be on the front of a truck-tractor instead of, or in addition to, the placarding on the front of the cargo body. Each placard on a transport vehicle, bulk packaging, freight container, or aircraft unit load device must:

• Be securely attached or affixed or placed in a holder.
• Be located clear of appurtenances and devices, such as ladders, pipes, doors, and tarpaulins.
• If practicable, be located so that dirt or water is not directed to it from the wheels of the transport vehicle.
• Be located away from any marking, such as advertising, that could substantially reduce its effectiveness and always at least 3 in. (76.0 mm) away from such marking.
• Have the words or the ID number, when authorized, printed on it and displayed horizontally, reading from left to right.
• Be maintained by the carrier in a condition so that the format, legibility, color, and visibility of the placard will not be substantially reduced because of damage, deterioration, or obscurement by dirt or other matter.
• Be affixed to a background of contrasting color or have a dotted or solid-line outer border that contrasts with the background color.