Site Help & Tools
For additional assistance or questions about IRIS, contact the IRIS Hotline at (202) 566-1676 (phone), (202) 566-1749 (FAX) or hotline.iris@epa.gov (email).
An Overview of the IRIS Web site
Welcome to the IRIS Web site & Database! This overview provides you with some information to help you navigate IRIS and understand the subject matter. This website conveys information on assessments posted to the database by the EPA’s IRIS Program as well as assessments under development.
For substances with assessments posted to the database, the IRIS website presents health effects information using three different formats:
For assessments under development, the IRIS website provides a tracking tool to help you monitor the status of upcoming substance assessments:
The A to Z List of IRIS Substances provides links to each of these health assessment formats and IRIS Track.Quick View
The IRIS QuickView presents a snapshot of the information available in the IRIS Summary and is intended to be a quick reference guide to key carcinogenic and noncarcinogenic data for each substance contained in the IRIS database. See either the IRIS Summary or the Toxicological Review for a more complete description and greater context.
The format of the QuickView parallels that of the IRIS Summary.
IRIS Summary
The IRIS Summary provides IRIS toxicity values and brief summaries of the information supporting those values, including the critical effect, the principal and supporting studies, uncertainty factors, and key references. The IRIS Summary also includes a revision history and list of synonyms for a given substance.
For more thorough analysis and documentation, a link to the pdf of the Toxicological Review is available on the IRIS Summary page for substances posted to the database since 1997.
Toxicological Review
The Toxicological Review provides scientific support and rationale for the hazard and dose-response risk information in IRIS human health assessments. All Toxicological Reviews are subjected to a full and open independent expert peer review process, including opportunity for public review and comment. Included in the document is information on chemical and physical properties, toxicokinetics, available pharmacokinetic modeling, hazard identification, mode-of-action and dose-response, as well as reference doses (RfD), reference concentrations (RfC), cancer slope factors and unit risks, and cancer descriptors that can be utilized in risk assessments. Toxicological Reviews are available for assessments posted to the IRIS database since 1997.
IRIS Track
The IRIS substance assessment tracking system (IRIS Track) is a compilation of status reports for EPA's IRIS assessments currently in progress. The status report shows the anticipated dates of major milestones, detailing where the substance assessment is in its development. Brief descriptions of the IRIS Track Milestones are listed below.
- Draft Development: A health scientist, referred to as a Chemical Manager, is assigned to each substance. The Chemical Manager is responsible for developing the draft assessment and shepherding draft documents though the review process and final ORD/NCEA approval. Development of a draft assessment consists of a literature search and preparation of a draft Toxicological Review (or other background document) and an IRIS Summary. The Chemical Manager may work with a team of toxicologists, epidemiologists, and statisticians in reviewing and analyzing the available literature. EPA's risk assessment guidelines form the basis for the analysis. This work is often supported by an EPA contractor.
- Agency Review: The draft assessment is reviewed by a standing group of senior health scientists representing EPA's Offices and Regions and by selected senior health scientists with scientific expertise relevant to the substance under review. The purpose of the IRIS Agency Review is to provide expert internal peer review and Agency-wide consultation to Chemical Managers and to ORD on whether the draft assessment is ready for external peer review and what issues should be raised.
- Interagency Review: The revised draft assessment is distributed through the Office of Management and Budget for review by other federal agencies.
- External Peer Review and Public Availability: EPA obtains external peer review, typically via a panel meeting that is open to the public. At this time, the draft assessment is posted on the internet for public comment.
- Final Assessment: Upon general agreement by Agency Reviewers, Interagency Reviewers, and ORD/NCEA senior management that peer review comments have been appropriately addressed, the assessment is approved by the NCEA Center Director. The final substance assessment is then uploaded to the IRIS Website.