This document is one of a series providing support for regulations issued by the U.S. Environmental Protection Agency (EPA) under Subtitle C of the Resource Conservation and Recovery Act (RCRA). The regulations represent the initial effort for nationwide control of hazardous waste from point of generation, through transportation, treatment, and storage, to point of ultimate disposal. This document deals with the subject of 'degree of hazard,' which says that hazardous wastes can be defined and grouped according to their degree of hazard (or level of risk to public health and the environment) and that management standards can be written defining management requirements corresponding to wastes of different degrees of hazard.