[Federal Register Volume 76, Number 4 (Thursday, January 6, 2011)]
[Notices]
[Page 787]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-20]
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ENVIRONMENTAL PROTECTION AGENCY
[EPA-HQ-ORD-2009-0605; FRL-9248-4]
Notice of Availability of the Recommended Toxicity Equivalence
Factors (TEFs) for Human Health Risk Assessments of 2,3,7,8-
Tetrachlorodibenzo-p-dioxin and Dioxin-Like Compounds
AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice of document availability.
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SUMMARY: The U.S. Environmental Protection Agency (EPA) is announcing
the availability of the final ``Recommended Toxicity Equivalence
Factors (TEFs) for Human Health Risk Assessments of 2,3,7,8-
Tetrachlorodibenzo-p-dioxin and Dioxin-Like Compounds'' (EPA/100/R-10/
005). The purpose of this document is to 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. This
guidance document summarizes the toxicity equivalence methodology,
provides background information and assumptions on how the methodology
has evolved, and recommends an approach for health risk assessors to
use to apply the methodology. EPA's Risk Assessment Forum (RAF) oversaw
the development of this document. Input was obtained from scientists
throughout the Agency, from interested members of the public, and from
external experts from a range of scientific disciplines via a
contractor-led peer review.
ADDRESSES: The final document is available electronically through the
EPA Office of the Science Advisor's Web site at: http://www.epa.gov/osa/raf/hhtefguidance/. A limited number of paper copies will be
available from EPA's National Service Center for Environmental
Publications (NSCEP), P.O. Box 42419, Cincinnati, OH 45242; telephone
number: 1-800-490-9198 or 513-489-8190; facsimile number: 301-604-3408;
e-mail: lmit.com">NSCEP@bps-lmit.com. Please provide your name, mailing address,
and title of the requested publication.
FOR FURTHER INFORMATION CONTACT: Julie Fitzpatrick, Risk Assessment
Forum Staff, Mail Code 8105R, Environmental Protection Agency, 1200
Pennsylvania Avenue, NW., Washington, DC 20460; telephone number: (202)
564-4212; facsimile number: (202) 564-2070; e-mail:
[email protected].
SUPPLEMENTARY INFORMATION: Dioxin and dioxin-like compounds (DLCs),
including polychlorinated dibenzo-dioxins (PCDDs), polychlorinated
dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs), are
structurally and toxicologically related halogenated dicyclic aromatic
hydrocarbons. Dioxins and DLCs are released into the environment from
several industrial sources, including chemical manufacturing,
combustion, and metal processing. There is global contamination of air,
soil and water with trace levels of these compounds. Typically, dioxins
and DLCs occur in the environment as chemical mixtures. Dioxins and
DLCs do not readily degrade; therefore, levels persist in the
environment, build up in the food chain, and accumulate in the tissues
of animals. Human exposures to these compounds occur primarily through
eating contaminated foods. The health effects from exposures to dioxins
and DLCs have been documented extensively in toxicological and
epidemiological studies.
Risk assessments have relied on the dioxin toxicity equivalence
factors (TEFs) approach. Various stakeholders, inside and outside the
Agency, have called for a more comprehensive characterization of risks.
Therefore, EPA's RAF identified a need to examine the current
recommended approach for application of the toxicity equivalence
methodology in human health risk assessments. An RAF Technical Panel
developed the draft guidance document, ``Recommended Toxicity
Equivalence Factors (TEFs) for Human Health Risk Assessments of
2,3,7,8-Tetrachlorodibenzo-p-dioxin and Dioxin-Like Compounds,'' to
assist EPA scientists in using this methodology to assess health risks
from dioxins and dioxin-like compounds, and inform EPA decision makers,
other agencies, and the public about this methodology.
An external expert peer review was conducted by both letter and an
open, public teleconference in October 2009. The peer review panel was
provided with the public comments received in the official public
docket for this activity under docket ID number EPA-HQ-ORD-2009-0605.
The peer review panel also had the opportunity to hear public comments
provided during the peer review teleconference. In preparing the final
document, EPA considered the public comments submitted to EPA's docket
during the public comment period and during the public teleconference,
and the recommendations from the external peer reviewers provided in
the peer review report and during the public teleconference.
EPA is currently addressing several issues related to dioxins and
dioxin-like chemicals in the environment. More information on these
activities is located at: http://www.epa.gov/dioxin/scienceplan/.
Dated: December 22, 2010.
Paul T. Anastas,
EPA Science Advisor.
[FR Doc. 2011-20 Filed 1-5-11; 8:45 am]
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