For many years, the National Academies of Sciences, Engineering, and Medicine has been asked to review assessments produced by the Integrated Risk Information System (IRIS) of the US Environmental Protection Agency (EPA). The reviews have consistently provided recommendations for revisions of specific assessments, but the National Academies committee that was tasked with reviewing the draft IRIS assessment of formaldehyde also suggested changes to improve the IRIS program itself, if EPA chose to do so. Since release of that committee’s report (NRC 2011), the IRIS program has been undergoing substantive changes. In 2014, another National Academies committee reviewed the changes in the IRIS program and provided an overall favorable assessment, noting that it was reviewing a work in progress (NRC 2014). In light of a change in leadership and continued revisions of the IRIS program, EPA asked the National Academies to review changes since 2014 and to determine whether they have been responsive to the recommendations in past National Academies reports. In response to EPA’s request, the National Academies convened the Committee to Review Advances Made to the IRIS Process, which prepared this brief report.
Given problems in several IRIS assessments noted by previous National Academies committees (see, for example, NRC 2006, 2010, 2011) and specific issues encountered in the formaldehyde assessment, the committee that evaluated the formaldehyde assessment provided a roadmap for reframing the development of IRIS assessments (Chapter 7, NRC 2011). The roadmap did not provide detailed guidance but rather suggestions for creating a more systematic and transparent IRIS process, if EPA chose to go forward with reforming the process. Congress directed EPA to respond to and incorporate the recommendations and suggestions provided in Chapter 7 of the 2011 National Academies report (House Report 112-151; Public Law 112-74). EPA indicated that the agency was committed to responding to National Academies recommendations and improving the IRIS program and began to make substantive changes. In a 2012 report to Congress, EPA highlighted its intended changes, such as a new document structure with a preamble that describes general methods for evidence identification, evidence evaluation, and derivation of toxicity values; new systematic approaches for data analysis; and expanded efforts for stakeholder engagement (EPA 2012; NRC 2014). EPA also noted that it had formed the Chemical Assessment Advisory Committee under the auspices of its Scientific Advisory Board to advise the agency on specific assessments and broader program issues. To ensure that EPA was responding adequately to National Academies recommendations, Congress asked the National Academies to review the changes that EPA was implementing.
In 2014, the National Academies released the report Review of EPA’s Integrated Risk Information System (IRIS) Process (NRC 2014), which evaluated the changes that were being implemented in the IRIS program and assessed whether they were responsive to the recommendations and suggestions made in Chapter 7 of the 2011 report. 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 recommendations in the…formaldehyde report.” It urged EPA to adopt systematic review practices, framed the IRIS process
in the context of systematic review (see Figure 1-1), and provided specific recommendations on each step of the process (NRC 2014). Since release of the 2014 report, substantive efforts have been made to incorporate systematic review into the IRIS process, and EPA has now asked the National Academies to assess its progress.
The committee that was convened to address EPA’s request included expertise in toxicology, epidemiology, risk assessment, statistics, modeling, evidence integration, and systematic review; see Appendix A for biographic information on the committee. The verbatim statement of the committee’s task is provided in Box 1-1. As noted, the committee was asked to assess the changes that have been (or that are planned to be) implemented by EPA in response to National Academies recommendations. It is important to note that the committee was not asked to evaluate the overall value of the IRIS program, to recommend where IRIS should be located within the agency, or to review any specific chemical assessment. The committee was also not tasked with conducting a comprehensive review of the IRIS program; rather, it was asked to evaluate whether the current trajectory of the program agrees with past recommendations of the National Academies.
To address its task, the committee held a 1.5-day workshop during which EPA presented its progress to the committee. Multiple opportunities for stakeholder input were provided. Appendix B provides the workshop agenda. The committee reviewed EPA presentations (Appendix C), posters (Appendix D), recently released materials (EPA 2017, 2018a,b; Orme-Zavaleta 2018), and all materials submitted by stakeholders. To fulfill its task of evaluating EPA’s progress in implementing past National Academies recommendations, the committee decided to focus its attention primarily on recommendations made in the report Review of EPA’s Integrated Risk Information System (IRIS) Process (NRC 2014). Although the report Review of the Environmental Protection Agency’s Draft IRIS Assessment of Formaldehyde (NRC 2011) provided general suggestions for reforming the IRIS program, it primarily made recommendations specifically for revising the draft assessment of formaldehyde. It is important to note that the 2011 committee was not tasked with an extensive review of the IRIS program. The 2014 report considered the general suggestions provided in the 2011 report, reviewed the IRIS program specifically, and made numerous recommendations directed at the program. Therefore, the present committee considered the 2014 report as expanding on the suggestions provided in the 2011 report and thus evaluated EPA’s progress in addressing each recommendation in the 2014 report.
The present report is organized into two chapters and five appendixes. Chapter 2 presents the committee’s overall findings regarding advances made in the IRIS process. Appendix A provides biographic information on the committee. Appendixes B, C, and D provide the workshop agenda, EPA presentations made during the workshop, and EPA poster presentations, respectively. Appendix E details the committee’s findings concerning individual recommendations in the report Review of EPA’s Integrated Risk Information System (IRIS) Process (NRC 2014).
EPA (US Environmental Protection Agency). 2012. EPA’s Integrated Risk Information Program, Progress Report and Report to Congress. Office of Research and Development, U.S. Environmental Protection Agency [online]. Available: https://www.epa.gov/sites/production/files/2015-06/documents/iris_report_to_congress_2012.pdf [accessed February 27, 2018].
EPA. 2017. IRIS Assessment Plan for Chloroform [CASRN 67-66-3]. EPA/635/R-17/330. Integrated Risk Information System, National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Washington, DC.
EPA. 2018a. Systematic Review Protocol for the IRIS Chloroform Assessment (Inhalation) [CASRN 67-66-3]. EPA/635/R-17/486. Integrated Risk Information System, National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Washington, DC.
EPA. 2018b. IRIS Assessment Plan for Uranium (Oral Reference Dose) (Scoping and Problem Formulation Materials) [CASRN 7440-61-1]. EPA/635/R-17/787. Integrated Risk Information System, National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Washington, DC.
NRC (National Research Council). 2006. Health Risks from Dioxin and Related Compounds: Evaluation of the EPA Reassessment. Washington, DC: The National Academies Press.
NRC. 2010. Review of the Environmental Protection Agency’s Draft IRIS Assessment of Tetrachloroethylene. Washington, DC: The National Academies Press.
NRC. 2011. Review of the Environmental Protection Agency’s Draft IRIS Assessment of Formaldehyde. Washington, DC: The National Academies Press.
NRC. 2014. Review of EPA’s Integrated Risk Information System (IRIS) Process. Washington, DC: The National Academies Press.
Orme-Zavaleta, J. 2018. Response to the Request for Correction (RFC). Letter to Robert Holden, Liskow & Lewis, New Orleans, LA, from Jennifer Orme-Zavaleta, Principal Deputy Assistant Administrator for Science, Office of Research and Development, Washington, DC, January 25, 2018; Attachment 1. EPA Response to the Denka Performance Elastomers (DPE) Request for Correction of the Toxicological Review of Chloroprene (CAS No. 126-99-8) In Support of Summary Information on the Integrated Risk Information System (IRIS); Attachment 2. Systematic Review of Chloroprene [CASRN 126-99-80] Studies Published Since 2010 IRIS Assessment to Support Consideration of the Denka Request for Correction (RFC). January 2018 [online]. Available: https://www.epa.gov/sites/production/files/2018-01/documents/epa_repsonse_to_mr._holdren_jan_25_2018_complete.pdf [accessed February 9, 2018].