US EPA's IRIS pilot program: establishing IRIS as a centralized, peer-reviewed data base with agency consensus. Integrated Risk Information System

The US EPA's Integrated Risk Information System (IRIS) contains Agency consensus scientific positions and quantitative values on cancer and noncancer health effects that may result from lifetime oral or inhalation exposure to specific chemical substances in the environment. Combined with specific exposure assessment information, the summary health information in IRIS may be used as a source in evaluating potential public health risks from environmental contaminants. IRIS is available to the public via EPA's Internet server at http://www.epa.gov/iris. Originally developed for internal EPA use, IRIS usage has broadened since being made publicly available in 1988 to include the private and public sectors nationally and internationally. Up to 1995, IRIS summaries were generated from within various EPA Offices and Regions and reviewed by Agency Workgroups, one for cancer and one for noncancer endpoints, before entry onto IRIS. In response to the increasing usage and recognition of IRIS and suggestions for improvement, an IRIS Pilot program was initiated in 1995. The purpose of the Pilot was 3-fold: To improve efficiency in getting information on to IRIS; to improve documentation for the positions reported in IRIS summaries, including applying new methodologies and guidance; and to improve opportunity for public input including external peer review. A new infrastructure was put in place, consisting of a cross-Agency team of 'Chemical Managers', a Pilot Program Manager, and a set of Agency 'Consensus Reviewers'. Cancer and noncancer assessments were prepared in an integrated fashion for Pilot chemical substances, documented in 'Toxicological Reviews' and derivative IRIS summaries. Public input was emphasized via an initial data call and rigorous external peer review. A final step was Agency-wide consensus review by senior staff scientists representing EPA's Offices and Regions. EPA's experience with the Pilot is forming the basis for designing operational aspects of the long-term IRIS program.