Attributes of a Waste Classification System

Previous sections have presented technical and historical information on radiation and chemical risk assessment and on classification of radioactive and hazardous chemical wastes. This information provides important perspectives for establishing the foundations of a new hazardous waste classification system. Before establishing these foundations, it is useful to specify the attributes that an ideal waste classification system should possess. The following sections identify the desirable attributes of a waste classification system including that the system should be risk-based, it should allow for exemption of waste, and it should be comprehensive, consistent, intrinsic, comprehensible, quantitative, compatible with existing systems, and flexible. These attributes should be recognized as goals that are not all likely to be fully realized in a practical waste classification system. 

Society desires that waste disposition activities be conducted in a manner that provides long-term protection of human health. Many measures of long-term protection have been developed over the 

There are two possible alternatives to using risk directly as the basis for waste classification non-risk-based systems and surrogate systems. Non-risk-based systems could use any conceivable attribute of hazardous waste as a basis for classification, including its source (see Sections 4.1 and 4.2 for examples) or the date it was produced. These bases are at best somewhat related to risk and at worst are totally unrelated. Because of this variable relationship, the use of non-risk-based approaches to waste classification could result in an unacceptable risk if the waste is managed in a way that does not provide adequate long-term protection, or an inappropriate allocation of resources if relatively innocuous wastes are managed in the same way as much more hazardous wastes. 

For hazardous chemical waste, there is no federal classification system other than a specification that the waste is hazardous or that it can be managed as if it were nonhazardous because it has been shown not to be characteristically hazardous or has been delisted or specifically excluded.14 Hazardous chemical waste that is not 

Allowing for exemption of waste materials that contain sufficiently small amounts of hazardous substances is a potentially important means of balancing the resources required to manage waste and the benefits in health risks averted. As a consequence of the discussion in Section 5.1, it is desirable that the definition of waste that can be exempted and, thus, managed as if it were nonhazardous should be risk-based. Furthermore, waste should be exempted based on the consideration that the associated risks should not exceed levels generally regarded as negligible. 

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Section 5 discusses the desirable attributes of a waste classification system and evaluates present classification systems with respect to these attributes. These discussions essentially summarize the rationale for the development of a comprehensive and risk-based hazardous waste classification system. 

Another desirable attribute of a waste classification system that is a corollary of the system being risk-based is that it treat wastes that pose similar health risks consistently. A chemically hazardous waste estimated to pose a certain risk should be in the same waste class as a radioactive waste that poses an equivalent risk, and similarly for mixed waste. Consistency also implies that wastes posing similar risks could be disposed of using essentially the same technology (municipal/industrial landfill, licensed near-surface facility for hazardous waste, or geologic repository). 

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