EPA Checks Science on 4 Chemical Assessments

The U.S. Environmental Protection Agency is holding four ongoing IRIS (Integrated Risk Information System) assessments pending a review of some of the underlying studies used in the assessments.

EPA conducts IRIS assessments to determine the impact of specific chemicals on human health.

The agency is holding these assessments due to a report from the National Toxicology Program (NTP) that outlines a recent review of a research study completed by the Ramazzini Institute, a lab in Italy that conducts animal testing to evaluate the potential cancer-causing effects of chemicals. The report discusses findings from a recent assessment by pathologists of an animal study on methanol. The report recommends that further pathology reviews be carried out to resolve differences of opinion between NTP scientists and the Ramazzini Institute in the diagnoses of certain cancers reported in the study.

Out of an abundance of caution and to ensure the agency’s chemical assessments are grounded in the soundest possible science, EPA undertook a thorough review of all ongoing and previous chemical assessments to determine which, if any, relied substantially on cancer testing from the Ramazzini Institute.

EPA found six assessments that significantly rely on data from Ramazzini cancer studies.

Ongoing chemical assessments on methanol, MTBE, ETBE and acrylonitrile have been placed on hold and the agency will determine whether the questions raised by NTP will require EPA to revise the assessments or take additional action to verify the data used in these assessments. EPA also postponed an Aug. 23 meeting of the agency’s Science Advisory Board, which had been previously scheduled to review the draft methanol assessment.

Out of more than 540 completed assessments posted on IRIS, EPA identified two – vinyl chloride and 1,1- dichloroethylene – that relied substantially on findings from Ramazzini Institute cancer studies. EPA is reviewing these assessments as well to determine what action is needed to assure their scientific integrity.

EPA will continue its review to determine if any other assessments are significantly impacted.