The Food Quality Protection Act (FQPA) of 1996 requires the United States Environmental Protection Agency (EPA) to assess the cumulative risks to human health that can result from exposure to pesticides and other substances that are toxic by a common mechanism. Such assessments will play an increasingly important role in the evaluation of risks posed by pesticides, and will improve the Agency’s ability to make regulatory decisions that fully protect public health and sensitive subpopulations, including infants and children. The identification of pesticides and other substances that cause a common toxic effect by a common mechanism is the first step of the cumulative risk assessment process.

This document describes the approach that EPA will use for identifying pesticides and other substances that cause common toxic effects by common mechanisms of toxicity. Specifically, this document describes:

• EPA’s interpretation of common mechanism of toxicity with respect to making a determination of safety;
• the specific steps that will be taken for identifying mechanisms of toxicity of pesticides and other substances that cause a common toxic effect;
• the types of data and their sources that are needed;
• how these data are to be used in reaching conclusions regarding commonality of mechanisms of toxicity; and
• criteria the Agency will use for categorizing pesticides and other substances for purposes of cumulative risk assessments.

Details on the other aspects of the cumulative risk assessment process will be discussed in a separate document. 

• Guidance for Identifying Pesticide Chemicals and Other Substances that have a Common Mechanism Toxicity (PDF)(14 pp, 252 K)