Document Type


Publication Date



toxicology, toxicological database, environmental regulation, Environmental Protection Agency


This white paper is a collaborative effort of Members Scholars and staff of the Center for Progressive Reform.


The Environmental Protection Agency’s (EPA) Integrated Risk Information System (IRIS) is the most important toxicological database in the world. Not only is it the single most comprehensive database of human health information about toxic substances, it also serves as a gateway to regulation, as well as to a range of public and private sector efforts to protect against toxic substances. IRIS “profiles” of individual substances include a number of scientific assessments of the substance’s toxicity to humans by various means of exposure – by inhalation, contact with the skin, and so on. Federal regulators rely on the assessments to do their important work protecting the public, as do state and local environmental protection authorities, and industry itself. Unfortunately, IRIS is woefully incomplete. EPA is many years behind in meeting statutory mandates for completing profiles of at least 255 chemicals, and as a result regulatory and enforcement action related to those chemicals has been stalled. Some chemical profiles in IRIS are missing information essential to regulatory action. In addition, 77 of the hazardous air pollutants (HAPs) listed in IRIS are missing the most important piece of information – an assessment of how much of the substance may be safely inhaled. In all, some 109 chemical profiles that EPA was required by the Clean Air Act Amendments of 1990 to have completed by 2008 are either included in IRIS but missing critical elements, or entirely absent from the database. So severe is the delay in the IRIS process that a 2008 Government Accountability Office (GAO) report warned that the Bush Administration’s approach to IRIS, which resulted in just two completed profiles per year, left the database at risk of becoming obsolete. To close data gaps and reestablish IRIS’s credibility as a cutting-edge database, EPA needs to make four changes. First, EPA should reduce the procedural burdens that were formalized during the Bush administration. Second, EPA must articulate clear, statute-driven priorities about which assessments to complete to ensure that data gaps in statutory mandates would be more quickly addressed. Third, the IRIS process must be restructured to allow for timely assessments made based on the weight-of-the-evidence at the time an assessment is undertaken. Fourth, EPA must also have adequate resources and make better use of its resources to complete a much larger number of assessments than it is currently finishing each year.


Environmental Law