A Type A container, on the other hand, is designed to survive normal transportation handling and minor accidents. Type B containers must be able to survive severe accidents. Markings on packages, labeling, and placarding on transportation vehicles are also important aspects of the transport of radioactive materials. Markings are designed to provide an explanation of the contents of a package by using standard terms and codes. 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.