Summary

Over the past several years, the US Environmental Protection Agency (EPA) 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 2011 report from the National Academies of Sciences, Engineering, and Medicine that reviewed a draft IRIS assessment of formaldehyde. In 2014, the National Academies released a report that reviewed the IRIS program and evaluated the changes implemented in it since the 2011 report. Although it provided many recommendations, the 2014 report concluded that “substantial improvements in the IRIS process have been made, and it is clear that EPA has embraced and is acting on the [National Academies] recommendations.”

Since 2014, new leadership of EPA’s National Center for Environmental Assessment (NCEA) and IRIS program has instituted even more substantive changes in the IRIS program in response to the recommendations in the 2014 report. Given the new direction of the IRIS program, EPA asked the National Academies to review the agency’s progress toward addressing the past recommendations. Accordingly, the National Academies convened the Committee to Review Advances Made to the IRIS Process. The present committee heard presentations, reviewed posters, and received demonstrations of toolkits and databases from EPA over the course of a 1.5-day workshop, and it reviewed recent IRIS work products. This brief report provides the committee’s general findings regarding EPA’s progress (Chapter 2) and specific findings regarding changes made in response to individual recommendations from the 2014 report (Appendix E).

Overall, the committee was impressed with the changes being instituted in the IRIS program since the 2014 report. The committee views the transformation of the IRIS program as a work in progress, recognizes that this review assesses one moment in time in a still-evolving program, and acknowledges that the IRIS program will (and should) continue to evolve as it adapts and applies new scientific approaches and knowledge. The change in NCEA and IRIS leadership has led to substantive reforms, and there is strong evidence that systematic review methods are being developed and implemented and that there is a commitment to use systematic-review methods to conduct IRIS assessments. Although the committee offers some refinements and identifies a few possibilities for further development in Chapter 2, its overall conclusion is that EPA has been responsive and has made substantial progress in implementing National Academies recommendations.