What is the requirement for vehicles carrying only White I or Yellow II labeled packages?

Vehicles carrying only White I or Yellow II labeled radioactive materials are not required to display a radioactive placard. This stems from the classification of these materials under the U.S. Department of Transportation regulations, which categorize them based on their radiation levels. White I packages emit the lowest radiation, while Yellow II packages have slightly higher levels but are still considered low-risk in terms of transportation safety.

The absence of a placard requirement for these categories signifies that they pose minimal risk of radiation exposure to the public and environment during transit. The regulations aim to streamline the transportation process for low-risk materials while only necessitating placarding for higher-risk categories that demand greater public awareness and safety measures.