An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Risk Assessment

Framework for Cumulative Risk Assessment

Several recent reports have highlighted the importance of understanding the aggregation of risks from multiple environmental stressors. These include the National Research Council's (NRC) 1994 report Science and Judgment in Risk Assessment and the 1997 report by the Presidential/Congressional Commission on Risk Assessment and Risk Management entitled Risk Assessment and Risk Management in Regulatory Decision-Making.

In addition, recent legislation, such as the Food Quality Protection Act of 1996, directed EPA to move beyond single chemical assessments and to focus, in part, on the cumulative effects of chemical exposures occurring simultaneously. Further emphasizing the need for EPA to focus on cumulative risks are the cases filed under Title VI of the 1964 Civil Rights Act. These cases have demanded a population-based approach to assessing human health risks from environmental contaminants.

The Framework is the first step in a long-term effort to develop cumulative risk assessment guidance. Building on EPA's growing experience with cumulative risk assessment, the Framework identifies the basic elements of the cumulative risk assessment process and provides a flexible structure for conducting and evaluating cumulative risk assessment, and for addressing scientific issues related to cumulative risk.

Although this Framework report will serve as a foundation for developing future guidance, it is neither a procedural guide nor a regulatory requirement within EPA, and it is expected to evolve with experience. The Framework is not an attempt to lay out protocols to address all the risks or considerations that are needed to adequately inform community decisions. Rather, it is an information document, focused on describing various aspects of cumulative risk.

This document has benefited from extensive peer input. Earlier drafts of the documents served as background pieces for peer consultations with state, federal and other peer groups. An external peer review, open to the public, was held in June 2002. The document was revised based on input received during the peer consultation and review processes and from public review and comment.


U.S. EPA. Framework for Cumulative Risk Assessment. U.S. Environmental Protection Agency, Office of Research and Development, Center for Public Health and Environmental Assessment (CPHEA), formerly known as the National Center for Environmental Assessment (NCEA), Washington Office, Washington, DC, EPA/600/P-02/001F, 2003.

Document Details and Links

The report's primary purpose is to offer a simple, flexible structure for conducting and evaluating cumulative risk assessment within EPA. Although this framework report will serve as a foundation for developing future guidelines, it is neither a procedural guide nor a regulatory requirement within EPA, and it is expected to evolve with experience. This report is intended to foster consistent approaches to cumulative risk assessment within EPA, identify key issues and define terms used in these assessments.

The Fact Sheet was created in response to the increasing focus on cumulative risk - the combined risks from aggregate exposures to multiple agents or stressors - EPA has begun to explore cumulative approaches to risk assessment. Cumulative risk assessment is an analysis, characterization, and possible quantification of the combined risks to human health or the environment from multiple agents or stressors. EPA will use this Framework as a basis for future guidance as EPA continues with assessment activities related to cumulative risk.

You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to learn more.