Dioxin Toxicity Equivalency Factors (TEFs) for Human Health (External Review Draft)

Recommended Toxicity Equivalency Factors (TEFs) for Human Health Risk Assessments of Dioxin and Dioxin-Like Compounds

Document Links

Full Draft Document (PDF) (29 pp, 241 KB, About PDF)
Peer Review Charge (PDF) (2 pp, 20 KB, About PDF)
Peer Review Summary Report (PDF) (57 pp, 175 KB, About PDF)

Federal Register Notice

Federal Register Notice, September 2, 2009 (PDF) (2 pp, 70 KB, About PDF)
Federal Register Notice, October 16, 2009 (PDF) (2 pp, 69 KB, About PDF)

Risk Assessment Forum

The U.S. Environmental Protection Agency is currently addressing several issues related to dioxins and dioxin-like chemicals in the environment. These include the comprehensive human health and exposure assessment for dioxin, commonly called the "dioxin reassessment," and a review of dioxin soil clean-up levels currently in use across the United States. As part of these efforts, the Agency is seeking public comment on the draft report entitled, "Recommended Toxicity Equivalency Factors (TEFs) for Human Health Risk Assessments of Dioxin and Dioxin-Like Compounds."

This document describes EPA's updated approach for evaluating the human health risks from exposures to environmental media containing dioxin-like compounds. It recommends the use of consensus TEF values for 2,3,7,8-tetrachlorodibenzo-p-dioxin and dioxin-like compounds, which were published in 2005 by the World Health Organization, and adopted by EPA in 2008 for ecological risk assessments.

The draft document was developed by the EPA's Risk Assessment Forum with extensive input from scientists throughout the Agency. The draft document summarizes the toxicity equivalence methodology, provides background information and assumptions on how the methodology has evolved, and provides health risk assessors with a recommended approach for application. It will assist EPA scientists in using the toxicity equivalence methodology to assess health risks from dioxins and dioxin-like compounds, as well as inform EPA decision makers, other agencies, and the public about this methodology.

Public Comment and External Peer Review

To submit comments relating to this document, please visit www.regulations.gov and search under Docket ID No. EPA-HQ-ORD-2009-0605.

All comments received through the docket will be shared with an external peer review panel for their consideration. The external peer review will be conducted by letter and open teleconference in the fall 2009 time frame.

In accordance with EPA's Science Plan for Activities Related to Dioxins in the Environment released May 26, 2009, the Agency is anticipating release of the final document by December 31, 2009.