Labels are used to visually indicate the type of hazard and the level of hazard contained in a package. Labels rely principally on symbols to indicate the hazard. Radioactive material is the only hazardous material which has three possible labels, depending on the relative radiation levels external to the package. Also, labels for radioactive material are the only ones which require the shipper to write some information on the label. The three labels are commonly called White I, Yellow 11, and Yellow III, referring to the color of the label and the roman numeral prominently displayed.
Placards are just bigger labels which are placed on the outside of the vehicle.
Unlike labels, there is only one placard and no information need be written on it. Placards on a vehicle are only required if the vehicle is carrying a package bearing a Yellow III label or is carrying low specific radioactive material. The safety record of storing and shipping used fuel is no accident. It is the result of a philosophy that places public safety and environmental protection first, and a practice of controlled handling and packaging of the used fuel so that it cannot harm the workers, the public, or the environment. Some of it is radioactive 2.