Review of U.S. EPA's ORD Staff Handbook for Developing IRIS Assessments

The U.S. Environmental Protection Agency's (EPA) Integrated Risk Information System (IRIS) program develops human health assessments that focus on hazard identification and dose-response analyses for chemicals in the environment. The ORD Staff Handbook for Developing IRIS Assessments (the handbook) provides guidance to scientists who perform the IRIS assessments in order to foster consistency in the assessments and enhance transparency about the IRIS assessment process. At the request of the EPA, this report reviews the procedures and considerations for operationalizing the principles of systematic reviews and the methods described in the handbook for determining the scope of the IRIS assessments, evidence integration, extrapolation techniques, dose-response analyses, and characterization of uncertainties.Table of ContentsFront MatterSummary1 Introduction2 Overview of Organization and Content of the Handbook3 Planning Assessments4 Study Evaluation5 Evidence Synthesis6 Evidence Integration7 Hazard Considerations and Study Selection for Deriving Toxicity ValuesReferencesAppendix A: Committee Member BiosketchesAppendix B: 2020 IRIS Handbook Organization and Contents and EPA Questions to the CommitteeAppendix C: Open Session Agendas