Final answer:
A 24 hour number is required on shipping documents for the transportation of hazardous materials to ensure immediate emergency contact. ERAPs are needed for the transport of specific high-risk hazardous materials to outline proper emergency response actions.
Step-by-step explanation:
The requirements for a 24 hour number and Emergency Response Assistance Plans (ERAPs) typically pertain to the transportation of hazardous materials or dangerous goods. The 24 hour number is a contact number that must be included in the shipping documents which can be reached at any time in the event of an emergency involving the shipped goods. This number is usually required for shipping hazardous materials so that appropriate emergency response can be coordinated if necessary.
ERAPs are required when transporting certain quantities of hazardous materials that pose a high risk to public safety should an accident occur. These plans detail the actions that need to be taken during an emergency and often need to be filed with and approved by the appropriate government regulatory body before transportation. ERAPs are generally necessary for materials that are toxic, highly reactive, or otherwise capable of causing significant harm to people, property, and the environment.