September 24, 1998

EPA-SAB-EPEC-CON-98-008

Honorable Carol M. Browner
Administrator
U.S. Environmental Protection Agency
401 M Street, SW
Washington, DC 20460

             Subject:      Notification of a Consultation on the Use of Toxic Equivalency
                          Factors (TEFs) in Ecological Risk Assessments

Dear Ms. Browner:

       The Ecological Processes and Effects Committee (EPEC) of the Science Advisory Board
(SAB) met on July 9,  1998, in part to conduct a consultation with staff from the Risk Assessment
Forum in the Office of Research and Development on a proposed framework for the application
of Toxic Equivalency  Factors (TEFs) for dioxins, furans, and polychlorinated biphenyls (PCBs) to
ecological risk assessment.  The SAB has developed the consultation as a mechanism to advise
the Agency on technical issues that should be considered in the development of regulations,
guidelines, or technical guidance before the Agency has taken a position.  A consultation is
conducted under the normal requirements of the Federal Advisory Committee Act, which include
advance notice of the  public meeting in the Federal Register.

       As is our customary practice, there will be no formal report from the SAB as a result of
this consultation, nor do we expect any formal response from the Agency.

                                        Sincerely,
  r. Joan M. Daisey, Chair                       Dr. Mark A. Harwell, Chair
Science Advisory Board                         Ecological Processes and
                                                Effects Committee
                                              Science Advisory Board

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