Establishing a Waste Classification System Based on the Framework and Risk Index

5 Establishing a Waste Classification System Based on the Framework and Risk Index 

1 Process of Implementing the Waste Classification System. Taken together, the framework for waste classification discussed in Section 6.2 and the risk index developed in Section 6.3 and this Section constitute the foundations of a comprehensive and risk-based hazardous waste classification system. Such a waste classification system could be established by regulatory authorities using the following general process  

For each substance of concern that causes deterministic effects (hazardous chemicals only), establish nominal thresholds for induction of deterministic responses in humans, taking into account all organs and tissues at risk. Then, establish organ-specific negligible and acceptable doses of each substance by applying appropriate safety and uncertainty factors to the assumed thresholds. 

Establish generic exposure scenarios for inadvertent human intrusion into a municipal/industrial landfill for disposal of exempt waste and intrusion into a dedicated near-surface facility for disposal of low-hazard waste. 

For each generic exposure scenario to be used in classifying waste, and taking into account all relevant exposure pathways in each scenario, calculate the dose per unit concentration of each hazardous substance in the waste. These doses generally would be the highest values calculated over an assumed time frame for the risk assessment (see Section 6.4.5.3), taking into account the time-dependence of the concentrations of hazardous substances in the waste. For example, the quantity calculated for radionuclides would be the annual effective dose (sievert) per unit activity concentration (Bq nr3), and the quantity calculated for hazardous chemicals would be the dose (intake, mg kg 1 d-1) per unit concentration (kg m 3). 

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