Waste classification system characteristically hazardous

Management and disposal of many wastes that contain hazardous chemicals are regulated by the U.S. Environmental Protection Agency (EPA) under authority of the Resource Conservation and Recovery Act (RCRA). In the classification system for hazardous chemical wastes specified in 40 CFR Part 261, waste is classified as hazardous by its characteristics or by listing. 

Section 7 then addresses the implications of the recommended risk-based waste classification system. By assuming key parameters (e.g., values of acceptable risk, characteristics of exposure scenarios) and applying the system to a variety of example waste streams, the question of how existing wastes would be classified in the new system is investigated. This Section also summarizes the legal and regulatory ramifications of the proposed hazardous waste classification system. 

Discussion of EPA s Hazardous Waste Classification System. Waste that is hazardous because it is ignitable, corrosive, or reactive, as defined above, must be treated to remove these characteristics prior to disposal. Examples of appropriate treatment methods... 

Significant parts of the existing waste classification systems are based on intrinsic properties of waste. The system for subclassifying low-level waste in 10 CFR Part 61 (NRC, 1982a) and the determination of whether a chemical waste is characteristically hazardous (see Section 4.2.1.1) are examples of waste classification based on intrinsic properties. 

NCRP reiterates that the risk-based waste classification system developed in this Report does not, and cannot, obviate the need to establish waste acceptance criteria at each hazardous waste disposal site based on the characteristics of the site, the particular disposal technology, and characteristics of the wastes that are intended for disposal at the site. NCRP expects that most waste that would be assigned to a particular class will be acceptable for disposal using the associated type of disposal technology indicated in Figure 6.1. However, the disposal capabilities of particular sites and engineered systems can vary substantially and can depend on the waste characteristics. The primary function of any waste classification system is to facilitate development of cost-effective approaches to waste management and disposal and effective communication on waste matters (see Section 2.1.2). 

Development of a comprehensive and risk-based hazardous waste classification system, in which waste classes are defined in relation to types of disposal systems that are expected to be generally acceptable in protecting public health, would not obviate the need to establish waste acceptance criteria at each disposal site based on the characteristics of the site and engineered disposal facility and the properties of wastes intended for disposal therein. The primary purposes of a hazardous waste classification system are to facilitate cost-effective management and disposal of waste and effective communication on waste matters. 

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... 

The proposed framework for risk-based classification of all radioactive and hazardous chemical wastes developed in Section 6.2.2 represents waste classification in its broadest, most general terms. Thus, this classification system can be viewed as the highest level of a possible hierarchy of hazardous waste classifications (e.g., see Figure 4.2). Further subclassification of these broadly defined waste classes may be desirable for such purposes as protection of workers during waste operations, protection of public health and the environment following waste disposal, and development of efficient methods of waste management taking into account the characteristics of actual wastes. 

One of the most promising technical approaches to regulation of hazardous wastes (and one that already seems in progress for evaluation and response to old problem sites) is the development of a degree of hazard system of waste classification. The current RCRA approach and, to a slightly lesser degree, the Louisiana approach tend to treat all hazardous wastes as about equal. In fact, however, it is apparent that waste materials differ very greatly over a spectrum of intensity of the characteristics that make them hazardous. This is particularly so for the characteristic of toxicity. 

Classification of a given waste is based on an evaluation of the risk index specified in Equations 6.4, 6.5 and 6.6 for assumed types of disposal systems. If the risk index is less than unity, the waste is acceptable for inclusion in the associated waste class otherwise, the waste generally requires a more protective disposal system and would be placed in a class for more hazardous wastes. The appropriate classification depends on the level of protection required which, in turn, depends on the characteristics of the waste relative to the capabilities of assumed disposal technologies. This concept is a fundamental part of the risk index. General assumptions about... 

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