Download PDF
September 18, 2012

NRC Committee on IRIS Process Holds Public Session

The ACTA Group

The National Research Council (NRC) Committee to Review the Integrated Risk Information System (IRIS) Process held its first meeting on September 17-18, 2012, opening with a public session on September 17, 2012. The U.S. Environmental Protection Agency (EPA) has asked NRC to review the IRIS process and changes being implemented or planned by EPA, and recommend modifications or additional changes as appropriate to improve the scientific and technical performance of the IRIS Program. According to the Committee’s website, the Committee will focus on the development of the IRIS assessments rather than the review process that follows draft development. The Committee’s website states that, “[b‌]ecause several reviews of IRIS assessments have expressed concerns about EPA’s weight-of-evidence analyses, the committee will review current methods for evidence-based reviews and recommend approaches for weighing scientific evidence for chemical hazard and dose-response assessments.” Speakers during the September 17 meeting included EPA’s Dr. Kenneth Olden, Director of the National Center for Environmental Assessment (NCEA), and Dr. Vincent Cogliano, Acting Director of the IRIS Program. The public session also included a discussion concerning weight-of-evidence. This discussion centered on the current methods and guidelines the IRIS Program follows in synthesizing data and how to best weigh the relevance of results when problems arise in the types of studies available for a particular chemical (e.g., lack of animal studies, issues with exposure route, or exposure levels).

Olden, who directed the National Institute of Environmental Health Sciences and National Toxicology Program from 1991 through 2005, joined EPA in July. He began his remarks by stressing the need for openness and transparency as the new hallmark for NCEA going forward. Olden noted that, if EPA and stakeholders do not agree on the definition of the problem at the beginning of the IRIS process, it is unlikely EPA and stakeholders will agree on the IRIS assessment at the end. Olden suggested that, in the future, EPA meet with stakeholders during the scoping and problem formulation phase of development to identify relevant health endpoints, reliable studies, and whether data gaps exist, and if so, explore options for obtaining additional data. This would prevent EPA from preparing an IRIS assessment based on incomplete data and being criticized by stakeholders.

According to Olden, EPA will seek public involvement earlier in the process, before a draft IRIS assessment is published and prior to the independent peer review of the draft assessment. Under the current IRIS process, a public listening session is held concurrently with the peer review, and the scope of the peer review does not include whether EPA has responded to public comments. Olden proposed that, by holding the public listening session first, the peer reviewers can review public comments submitted on the draft assessment and determine whether EPA has responded adequately to them. Olden also suggested that stakeholders could be engaged in preparing the charge for the peer reviewers. After the peer review process is complete, Olden also suggested that stakeholders be allowed to review and comment on the resulting peer reviewed draft, which will eliminate the current practice of using the interagency review process to voice stakeholder concerns through other federal agencies. Olden stated his desire to enhance the expertise of his own staff, stressing more leaders with strong science and management backgrounds, including a risk assessment expert.

In April 2011, the NRC Committee to Review EPA’s Draft IRIS Assessment of Formaldehyde issued its report on the draft assessment, but went beyond the scope of its charter, examining the process EPA uses to develop draft IRIS assessments. In 2009, EPA published a seven-step process for preparing IRIS assessments. Cogliano noted that the NRC’s 2011 recommendations focused on the first step in the process, developing the draft IRIS assessment, and that the steps for outside review are very well defined. EPA is now including a preamble in IRIS assessments, based on the NRC’s recommendations, that explains the analytical methods EPA uses in IRIS assessments generally. According to Cogliano, NRC’s recommendations provided focus on systematic methods for identifying and collecting pertinent publicly available studies, evaluating those studies, how to weigh the studies, how to select the most reliable and relevant studies to derive reference values and unit risk, and then how to calculate and examine the toxicity values derived in the studies. EPA now reviews the scientific literature first for information concerning health effects, then identifies studies for each effect. EPA calculates reference values for each effect, and then develops an overall reference value. Cogliano stated that deriving reference values for each effect is helpful in cases where an effect may not be widely applicable to the general population or if it is unclear whether an effect is an adverse effect.

According to EPA, it will update the new preamble to the IRIS assessments, and then hold an external peer review on it. EPA will forward the revised preamble to the NRC Committee for its review, and hopes to have it within the next few months. The preamble has already been reviewed within EPA and through its interagency review process. EPA has tentatively scheduled a weight-of-evidence workshop for March 2013. The next NRC Committee meeting will be held in December 2012, at which time EPA intends to have proposals for workshops and how they fit together.