IRIS Remains Under Fire

Risk Assessment/IRIS:

EPA’s Integrated Risk Information System (“IRIS”), which assesses the human health risks associated with chemical exposure, has come under fire from the head of the scientific panel charged by Congress to review the program.

In recent years, IRIS has been the subject of much criticism, causing Congress to direct a panel of the National Research Council (“NRC”), an arm of the National Academies, to review EPA’s assessment of arsenic and other chemicals and issue recommendations to improve “scientific and technical performance.” NRC is also currently conducting a review of the overall IRIS process for developing assessments and the current methods available for weight-of-evidence analyses, with the goal of recommending “approaches for weighing scientific evidence for chemical hazard and dose-response assessments.”

In 2011, NRC found fault with the agency’s IRIS assessment of formaldehyde, and EPA is in in the process of implementing some of the panel’s recommendations from that review.

However, EPA’s attempts to improve the program have provoked criticism from the very panel whose recommendations the agency is trying to adopt. At a December 18, 2012 meeting with EPA officials, the head of the NRC review panel, Professor Jonathan Samet of the University of Southern California Keck School of Medicine, raised concerns that EPA’s ongoing changes to the IRIS process presented the panel with a difficult “moving target.” Samet noted that “it seems like literally every aspect of the IRIS assessment process” is changing, complicating NRC’s review.

EPA’s newly revised IRIS process will be on display in its assessment of benzo[a]pyrene, which is expected to be released in coming months.

In another example of overlapping agendas, both EPA and NRC have planned upcoming events on weight-of-evidence assessments. Vince Cogliano, head of the IRIS program, told meeting attendees that EPA would coordinate with NRC so that the two events would be complementary and further strengthen weight-of-evidence analyses.

Meanwhile, EPA has also announced that it is “restarting” its IRIS assessment of arsenic. The new assessment process is expanded to include inhalation risks and will also combine studies of cancer and non-cancer effects for a broader overview of the chemical’s health risks. EPA held a January 8-9, 2013 workshop to gather public input on the assessment, the first meeting of its kind. The NRC panel reviewing the arsenic assessment will also collect public input and provide EPA with an interim report prior to EPA’s release of the draft assessment, which the panel will also peer review.