Why didn EPA use the (higher) unit risk estimate (URE) for formaldehyde reported in the Agencys Integrated Risk Information System (IRIS)?
EPA is currently updating the Integrated Risk Information System (IRIS) file for formaldehyde to consider new science published in the peer-reviewed literature including risk estimates developed by the CIIT Centers for Health Research (formerly the Chemical Industry Institute of Toxicology) and epidemiologic studies published by the National Cancer Institute and others. In 2004, EPA selected the CIIT-derived unit risk estimate (an estimate of cancer potency) of 5.9 x 10-9per µg/m3 during the development of the plywood and composite wood products air toxics regulation. Since this decision, considerable work on the part of EPA has been performed to evaluate the new studies as well as the CIIT modeling. However, at this time the evaluation, and hence the revision to the IRIS file for formaldehyde, is incomplete. Until EPA’s evaluation is complete, the Agency will continue using the CIIT value and will revisit this issue when we have more information. Top of page 15: How did EPA treat Coke
