DOT HAZARDOUS MATERIALS WARNING LABELS
Hazardous materials transported on roadways must carry a Department of Transportation warning label on the package. Vehicles transporting quantities of hazardous materials must have DOT placards affixed to all sides of the vehicle. Bulk shipments, such as in gasoline tanker trucks, will have a four digit number code instead of the hazard class in the center of the placard. This number can be referenced in the DOTs "Emergency Response Guide Book" to determine the identity and emergency handling for the chemical involved.