Over the past several years, the US Environmental Protection Agency has been transforming the procedures of its Integrated Risk Information System (IRIS), a program that produces hazard and dose?response assessments of environmental chemicals and derives toxicity values that can be used to estimate risks posed by exposures to them. The transformation was initiated after suggestions for program reforms were provided in a report from the National Academies. This report reviews the EPA’s progress toward addressing the the Academies' recommendations.