Final answer:
Class 7 (Radioactive materials) is the hazard class that uses the transport index to regulate the transported quantity in a vehicle; this index reflects the level of radiation exposure and ensures safety according to DOT and EPA regulations.
Step-by-step explanation:
The hazard class that uses transport index to determine the amount that can be loaded into a single vehicle is Class 7 (Radioactive materials). The transport index is a number assigned to radioactive packages, which indicates the level of control needed during transportation. The higher the transport index, the greater the potential radiation exposure, and therefore stricter controls on the quantity loaded are required to minimize the risks associated with the transportation of these materials. The transport index helps to ensure that radiation exposure to people and the environment does not exceed safe limits as specified by hazardous material regulations.
The transportation of hazardous waste, whether it is listed, characteristic, or mixed, must adhere to the regulations set forth by the United States Department of Transportation (DOT) and the Environmental Protection Agency (EPA). Proper handling, which includes classification, labeling, and determining the appropriate transport index when applicable, is critical for maintaining safety and environmental protection.