Waste classification, general definition

Report thus, the phrase risk-based waste classification system. The desirability of basing a waste classification system on risk has been recognized for many years (DOE, 1980). While risk will be defined more precisely in subsequent sections, the following general definition is useful at this point (Garrick and Kaplan, 1995) ... 

Generally applicable waste classification system proposed by Kocher and Croff. In response to the definition of high-level waste in Clause (B) of NWPA (1982) discussed in Section 4.1.2.3.1, Kocher and Croff (1987 1988) developed a proposal for a quantitative, generally applicable, and risk-based radioactive waste classification system that addresses the definitions of high-level waste in... 

The basic framework for the waste classification system developed in this Report is depicted in Figure 6.1. Starting with the objectives that the classification system should apply to any waste that contains radionuclides or hazardous chemicals and that all such waste should be classified based on risks to the public posed by its hazardous constituents, the fundamental principle of the proposed system is that hazardous waste should be classified in relation to disposal systems (technologies) that are expected to be generally acceptable in protecting public health. This principle leads to the definitions of three classes of waste, and to quantification of the boundaries of the different waste classes based on considerations of risks that arise from different methods of disposal. The boundaries normally would be specified in terms of limits on concentrations of hazardous substances. At the present time, nearly all hazardous and nonhazardous wastes are intended for disposal in a near-surface facility or a geologic repository, and these are the two types of disposal systems assumed in classifying waste. The three waste classes and their relationship to acceptable disposal systems are described in more detail in Section 6.2. 

The risk index in Equation 6.2 is expressed in terms of risk (i.e., the probability that an adverse response will occur during an individual s lifetime). This definition is consistent with the fundamental objective of developing a risk-based hazardous waste classification system. However, the use of health risk per se in calculating the risk index presents some difficulties because risk is not proportional to dose for substances that cause deterministic effects. For this type of substance, the risk is presumed to be zero at any dose below a nominal threshold. Since the allowable dose should always be less than the threshold in order to prevent the occurrence of adverse responses, expressing the risk index in terms of risk would result in an indeterminate value and, more importantly, a lack of distinction between doses near the nominal thresholds and lower doses of much less concern. For any hazardous substance, including carcinogens for which risk is assumed to be proportional to dose without threshold, it is generally useful to express the risk index as the ratio of a calculated dose [e.g., sieverts, mg (kg d)-1] to an allowable dose that corresponds to an allowable risk ... 

The risk index defined in Equation 6.1 (see Section 6.2.1) is intended to provide a measure of the potential risk that arises from disposal of any waste that contains hazardous substances. In Section 6.3, the general definition of the risk index is elaborated and recommendations on suitable approaches to calculating the risk index for individual hazardous substances are presented. For purposes of developing a comprehensive and risk-based waste classification system, a simple method of calculating the risk from disposal of mixtures of hazardous substances is needed. The method must take into account that the allowable concentrations of particular hazardous substances in waste of a given class generally will be lower when multiple substances are present than when only a single substance is present. Such a method is presented and discussed in this Section. 

These considerations lead to an important conclusion regarding the relationship between classification of fuel-cycle wastes and requirements for their disposal—namely, that the selection of acceptable systems for disposal of fuel-cycle wastes does not depend on the definitions of waste classes. Rather, the types of disposal systems that are expected to provide adequate protection of public health (e.g., a near-surface facility or a geologic repository) are selected based on the radiological properties of waste, essentially without regard for how the waste is classified. Thus, general requirements for disposal are not affected by the qualitative, source-based, and ambiguous definitions in the classification system for fuel-cycle waste. 

OSHA does not generally consider discarded feminine hygiene products to fall within the definition of regulated waste. These products should be discarded in waste containers which are lined in such a way as to prevent contact with the contents. OSHA notes, however, that it is the employer s responsibility to determine which job classifications or specific tasks and procedures involve occupational exposure. For example, the employer must determine whether employees can come into contact with blood during the normal handling of such products fi om initial pick-up through disposal in the outgoing trash. 

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