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Guidance on Cumulative Risk Assessment of Pesticide Chemicals that have a Common Mechanism of Toxicity

In assessing the potential health risks associated with exposure to pesticides, attention has historically focused on single pathways of exposure (e.g., from pesticide residues in food, water, or residential/nonoccupational uses) for individual chemicals, and not on the potential for individuals to be exposed to multiple pesticides by all pathways concurrently. In 1996, the Food Quality Protection Act (FQPA) imposed upon the Office of Pesticide Programs (OPP) the requirement to consider potential human health risks from all pathways of dietary and nondietary exposures to more than one pesticide acting through a common mechanism of toxicity.

This document provides guidance to OPP scientists for evaluating and estimating the potential human risks associated with such multichemical and multipathway exposures to pesticides. This process is referred to as cumulative risk assessment. The current guidance has been revised in light of review and comment offered by the public on an earlier draft version during the public comment period of June to September 2000, by the FIFRA Scientific Advisory Panel (SAP) in September and December 1999 and by comments offered by other external parties at the SAP meetings. 

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