The Integrated Risk Information System (IRIS) is a program within the US Environmental Protection Agency (EPA) that is responsible for developing toxicologic assessments of environmental contaminants. An IRIS assessment contains hazard identifications and dose-response assessments of various chemicals related to cancer and noncancer outcomes. Although the program was created to increase consistency among toxicologic assessments within the agency, federal, state, and international agencies and other organizations have come to rely on IRIS assessments for setting regulatory standards, establishing exposure guidelines, and estimating risks to exposed populations. Over the last decade, the National Research Council (NRC) has been asked to review some of the more complex and challenging IRIS assessments, including those of formaldehyde, dioxin, and tetrachloroethylene. In 2011, an NRC committee released its review of the IRIS formaldehyde assessment. Like other NRC committees that had reviewed IRIS assessments, the formaldehyde committee identified deficiencies in the specific assessment and more broadly in some of EPA's general approaches and specific methods. Although the committee focused on evaluating the IRIS formaldehyde assessment, it provided suggestions for improving the IRIS process and a roadmap for its revision in case EPA decided to move forward with changes to the process. Congress directed EPA to implement the report's recommendations and then asked the National Research Council to review the changes that EPA was making (or proposing to make) in response to the recommendations.
Review of EPA's Integrated Risk Information System (IRIS) Process provides an overview of some general issues associated with IRIS assessments. This report then addresses evidence identification and evaluation for IRIS assessments and discusses evidence integration for hazard evaluation and methods for calculating reference values and unit risks. The report makes recommendations and considerations for future directions. Overall, Review of EPA's Integrated Risk Information System Process finds that substantial improvements in the IRIS process have been made, and it is clear that EPA has embraced and is acting on the recommendations in the NRC formaldehyde report. The recommendations of this report should be seen as building on the progress that EPA has already made.
Table of Contents
|Review of EPA's Integrated Risk Information System (IRIS) Process||1-2|
|2 General Process Issues||17-29|
|3 Problem Formulation and Protocol Development||30-39|
|4 Evidence Identification||40-62|
|5 Evidence Evaluation||63-84|
|6 Evidence Integration for Hazard Identification||85-109|
|7 Derivation of Toxicity Values||110-134|
|8 Future Directions||135-139|
|Appendix A: Biographic Information on the Committee to Review the IRIS Process||140-143|
|Appendix B: Workshop Agenda on Weight of Evidence||144-149|
|Appendix C: Primer on Bayesian Method||150-154|
The National Academies Press (NAP) has partnered with Copyright Clearance Center's Rightslink service to offer you a variety of options for reusing NAP content. Through Rightslink, you may request permission to reprint NAP content in another publication, course pack, secure website, or other media. Rightslink allows you to instantly obtain permission, pay related fees, and print a license directly from the NAP website. The complete terms and conditions of your reuse license can be found in the license agreement that will be made available to you during the online order process. To request permission through Rightslink you are required to create an account by filling out a simple online form. The following list describes license reuses offered by the National Academies Press (NAP) through Rightslink:
Click here to obtain permission for the above reuses. If you have questions or comments concerning the Rightslink service, please contact:
Rightslink Customer Care
Tel (toll free): 877/622-5543
To request permission to distribute a PDF, please contact our Customer Service Department at 800-624-6242 for pricing.
To request permission to translate a book published by the National Academies Press or its imprint, the Joseph Henry Press, please click here to view more information.