Pursuant to 49 CFR 172.516(c)(2):

Each placard on a transport vehicle, bulk packaging, freight container or aircraft unit load device must—

(2) Be located clear of appurtenances and devices such as ladders, pipes, doors, and tarpaulins;

Placards must be located clear of appurtenances and devices on the vehicle.

Notice how the placard holders on this vehicle are placed higher in order to ensure they are visible when the lift gate – an “appurtenance” or “device” if I ever saw one – is stowed in place for transportation.

Can the placards be too high on the side or end of the vehicle?  Or, too low?  No, at least not as far as the Hazardous Material Regulations of the PHMSA/USDOT are concerned.  There is no mention in the HMR of the specific placement of HazMat placards on the vehicle as long as they appear on all four sides, “…on each side and each end…” pursuant to §172.504 and meet the further requirements of §172.516, one of which we see here.  Other requirements of §172.516(c) include:

• Placard must be securely attached to the vehicle or placed in a holder (as is the case in photo).
• So far as practicable, placard must be located so that dirt or water is not directed to it from the wheels of the transport vehicle.
• At a minimum the placard must be located at least 3 inches (76.0 mm.) away from any marking (such as advertising) that could make it harder to see.
• Text printed on the placard must be displayed horizontally, reading from left to right.
• Placard must be maintained by the carrier in good condition so that it doesn’t become unreadable due to dirt, damage, wear, &etc.
• Placard must be affixed to a background of contrasting color, or must have a dotted or solid line outer border which contrasts with the background color.

Contact me if you’re uncertain of how to display HazMat placards on any bulk packaging, freight container, unit load device, transport vehicle or rail car.