Risk management paradigms chemicals

Chemical Paradigm for Risk Management of Stochastic Responses... 

The chemical paradigm for risk management also is used in regulating exposures to hazardous chemicals that cause deterministic effects and exhibit a threshold in the dose-response relationship. For these substances, RfDs, which are often used to define acceptable exposures, represent negligible doses, because RfDs usually are well below assumed thresholds for deterministic responses in humans and action to reduce doses below RfDs generally is not required. This interpretation is supported by cases where doses above an RfD are allowed when achieving RfD is not feasible. A particular example... 

A proper reconciliation of the radiation and chemical paradigms for risk management is important to the development of a comprehensive and risk-based hazardous waste classification system. In particular, the proposed waste classification system developed in Sections 6.2 and 6.3 of this Report is based fundamentally on the concept that an acceptable risk generally can be substantially greater than a negligible risk. This distinction is used to define different classes of waste that pose an increasing hazard. 

Many fundamental concepts of human health risk assessment from chemical and biological hazards have been described in Risk Assessment in the Federal Government Managing the Process (NRC, 1983). The basic paradigm developed in that report is shown in Figure 6-1, and it captures the two key components—risk assessment and risk management—that apply equally well to building protection situations. 

The different approaches to management of stochastic risks for radionuclides and hazardous chemicals are referred to in this Report as the radiation and chemical paradigms (EPA, 1992a). The following discussion of the two paradigms for management of stochastic risks is adapted from previous papers (Kocher, 1999 Kocher and Hoffman, 1991). 

The chemical paradigm for management of stochastic risks is applied to control of exposures to stochastic chemicals under authority of several environmental laws. The chemical paradigm also applies to control of radiation exposures when these exposures are regulated under authority of any laws other than AEA. 

Fig. 3.12. The chemical paradigm for management of stochastic risks (Kocher, 1999).

Table 3.5—Differences in interpretations of acceptable and unacceptable risks in radiation and chemical paradigms for management of stochastic risks. ...

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