[Federal Register Volume 65, Number 113 (Monday, June 12, 2000)]
[Notices]
[Pages 36898-36900]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-14853]


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ENVIRONMENTAL PROTECTION AGENCY

[FRL-6714-9]


Draft Dioxin Reassessment Documents; Toxicity Equivalence Factors 
(TEFs) for Dioxin and Related Compounds and Integrated Summary and Risk 
Characterization for 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD) and 
Related Compounds

AGENCY: Environmental Protection Agency

ACTION: Notice of peer review workshop and public comment period.

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SUMMARY: The U.S. Environmental Protection Agency (EPA) is announcing 
that an EPA contractor will be organizing, convening, and conducting an 
external peer review workshop to review the external review draft 
documents entitled, Part II. Chapter 9: Toxicity Equivalence Factors 
(TEFs) for Dioxin and Related Compounds (hereafter, TEF chapter) and 
Part III. Integrated Summary and Risk Characterization for 2,3,7,8-
Tetrachlorodibenzo-p-Dioxin (TCDD) and Related Compounds (hereafter, 
Integrated Summary and Risk Characterization). The EPA is also 
announcing an extended public comment period for these two draft 
documents. The peer review workshop will be organized, convened, and 
conducted by the Eastern Research Group, Inc. (ERG), an EPA contractor 
for this external scientific peer review. The documents were prepared 
by the EPA's Office of Research and Development (ORD) and with the 
involvement of other federal agencies, in particular the National 
Institutes of Health's National Institute of Environmental Health 
Sciences. EPA will consider the peer review advice and public comment 
submissions in revising these draft dioxin reassessment documents in 
preparation for an upcoming review by EPA's Science Advisory Board 
(SAB).

DATES: The two-day peer review workshop will be held on Tuesday, July 
25, 2000, 9 a.m. to 5:30 p.m. and Wednesday, July 26, 2000, 8:30 a.m. 
to 5:00 p.m. Members of the public may attend as observers, and there 
will be a limited time for comments from the public. The extended 
public comment period begins June 12, 2000, and concludes two weeks 
following the SAB's peer review meeting on the dioxin reassessment 
which is scheduled for October 2000. The specific date of that meeting 
has not been determined. EPA will announce in a subsequent Federal 
Register (FR) notice the formal closing date of the public comment 
period.

ADDRESSES: The external peer review workshop will be held at the 
Holiday Inn Capital, 550 C Street, SW, Washington, DC 20024, Tel: 202-
479-4000. The Eastern Research Group, Inc. (ERG), an EPA contractor, is 
organizing, convening, and conducting the peer review workshop. To 
attend the workshop as an observer, please register by Monday, July 17, 
2000, by calling ERG at Tel: 781-674-7374, or send a facsimile to: 781-
674-2906. Space is limited, and registrations to attend will be 
accepted on a first-come, first-served basis. Time will be set aside 
each day to hear comments from observers. Individual comments will be 
limited to no more than 5 minutes per person, and the number of people 
giving oral comments will be limited by the time available. If you wish 
to make comments at the workshop, please sign up in advance by 
contacting ERG. Commenters will be scheduled on a first-come, first-
served basis. Please reference the ``EPA Dioxin Workshop'' when 
contacting ERG or the hotel.
    Document Availability: The primary distribution method for the 
external review drafts of the TEF chapter and Integrated Summary and 
Risk Characterization to the public will be via the Internet on ORD's 
National Center for Environmental Assessment (NCEA) website. These 
external review drafts are available at http://www.epa.gov/ncea/dioxin.htm. These documents can be viewed and downloaded from the 
Internet for review and comment. Background information is also 
available at the above-mentioned website. This information, provided as 
background only, consists of other exposure and health sections of the 
reassessment, specifically Part I: Estimating Exposure to Dioxin-Like 
Compounds (Volumes 2-4) and Part II: Health Assessment for 2,3,7,8-
Tetrachlorodibenzo-p-Dioxin (TCDD) and Related Compounds (Chapters 1-
8).
    In addition, a Compact Disk-Read Only Memory (CD-ROM) containing 
the external review draft of the TEF chapter and the background 
information, is available from EPA's National Service Center for 
Environmental Publications (NSCEP) in Cincinnati, Ohio (telephone: 1-
800-490-9198, or 513-489-8190; facsimile 513-489-8695). If you are 
requesting a copy of the CD-ROM, please provide your name, mailing 
address, and reference the ``Dioxin CD'' and Document number EPA/600/P-
00/001Ab-Ae. The background documents are available only on CD-ROM and 
the Internet.
    Also, a limited number of paper copies of only the draft TEF 
chapter and the Integrated Summary and Risk Characterization will be 
available from NSCEP. If you are requesting a paper copy of either the 
draft TEF chapter or draft Integrated Summary and Risk 
Characterization, please provide your name, mailing address, and the 
document title and number, Part II. Chapter 9: Toxicity Equivalence 
Factors (TEFs) for Dioxin and Related Compounds, Document number NCEA-
I-0836; and/or Part III. Integrated Summary and Risk Characterization 
for 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD) and Related Compounds, 
Document number EPA/600/P-00/001Ag. Copies of draft documents or 
background information are not available from ERG.
    Comment Submission: Comments may be mailed to the Technical 
Information Staff (8623D), NCEA-W, U.S. Environmental Protection 
Agency, 1200 Pennsylvania Avenue, NW., Ariel Rios Building, Washington, 
DC 20460, or delivered to the Technical Information Staff at 808 17th 
Street, NW., 5th Floor, Washington, DC 20006; telephone: 202-564-3261; 
facsimile: 202-565-0050. Comments should be in writing. Please submit 
one unbound original with pages numbered consecutively, and three 
copies of the comments. For attachments, provide an index, number pages 
consecutively with the comments, and submit an unbound original and 
three copies. Electronic

[[Page 36899]]

comments may be emailed to: [email protected].
    Please note that all technical comments received in response to 
this notice will be placed in a public record. For that reason, 
commentors should not submit personal information (such as medical data 
or home address), Confidential Business Information, or information 
protected by copyright. Due to limited resources, acknowledgments will 
not be sent.

FOR FURTHER INFORMATION CONTACT: For workshop information, 
registration, and logistics, contact ERG, 110 Hartwell Avenue, 
Lexington, Massachusetts, 02421-3136; Tel: 781-674-7374; Fax: 781-674-
2906.
    For information on the public comment period, contact Linda C. 
Tuxen, NCEA, telephone: 202-564-3332; facsimile: 202-565-0090; or 
email: [email protected]. This is an extended public comment period 
that will continue until the SAB meeting in the Fall 2000. It is very 
important to note that, as the dioxin reassessment process continues, 
two versions of the draft sections will be put on the dioxin website. 
The external review drafts, the availability of which are announced in 
this FR notice, will be replaced by the SAB review drafts in early 
September. The public is requested to make clear in their submitted 
comments on which draft document they are commenting.

SUPPLEMENTARY INFORMATION: In April 1991, EPA announced that it would 
conduct a scientific reassessment of the health risks of exposure to 
dioxin and dioxin-like compounds. Previous EPA dioxin assessment 
documents, one final and one draft, were completed in 1985 and 1988, 
respectively. EPA undertook the 1991 reassessment in light of 
significant advances in our scientific understanding of mechanisms of 
dioxin toxicity, significant new studies of dioxin's carcinogenic 
potential in humans and increased evidence of other adverse health 
effects. EPA has worked to make each phase of the dioxin reassessment 
an open and participatory process. These efforts have included the 
involvement of outside scientists as principal authors of several 
chapters, frequent public meetings to report progress and take public 
comment, and publication of early drafts for public comment and peer 
review. Early in the reassessment process, EPA held public meetings 
(1991 and 1992) to inform the public of the Agency's plans and 
activities for the reassessment, to hear and receive public comments 
and reviews of the proposed plans, and to receive any current, 
scientifically relevant information. In 1992 and 1993, the Agency 
convened three peer-review workshops to review early drafts of the 
reassessment chapters.
    In September 1994, EPA released the external review drafts of the 
health effects and exposure documents which amounted to over 2,200 
pages. In late 1994 EPA took public comment and held numerous public 
meetings across the country on the drafts, followed by SAB review of 
the draft dioxin reassessment in May 1995. The SAB's report was 
received in the Fall of that year. In its report to the Agency, the SAB 
responded favorably to most portions of the reassessment, but 
recommended substantive revision of two key sections. The SAB 
recommended the revision of these two sections, Chapter 8: Dose-
Response Modeling for 2,3,7,8-TCDD and the Risk Characterization 
document, and the development of an additional document that would 
focus on the toxicity equivalent factors (TEFs) for dioxin and dioxin-
like compounds. In addition to these substantive recommendations, the 
SAB suggested that the redrafting process include broader participation 
of outside scientists from both the public and private sectors. They 
also requested that the two redrafted chapters and the new TEF chapter 
be submitted to independent external peer review, before being returned 
to the SAB for re-review. With respect to Chapters 1-7 of the health 
document and the full exposure reassessment document, the SAB accepted 
these sections. They suggested that the sections be updated to address 
public and SAB comments and to incorporate new scientific data, but the 
SAB's report stated that substantive further review of these sections 
by the SAB was not needed.
    After receipt of the SAB's report, the Agency worked with over 40 
individual stakeholders from the private and public sectors, 
representing environmental, industry, academic, state, and other public 
interest and public health communities, on the next steps and to gather 
input on possible approaches for conducting the revision process. The 
Agency has tried to keep these individuals apprised of reassessment 
activities at critical points in the revision process. The Agency 
expects that these individuals will be important avenues of public 
comment on the draft documents.
    The final dioxin reassessment will consist of three parts. Part I: 
Estimating Exposure to Dioxin-Like Compounds focuses on sources, levels 
of dioxin-like compounds in environmental media, and human exposures. 
Part II: Health Assessment for 2,3,7,8-Tetrachlorodibenzo-p-Dioxin 
(TCDD) and Related Compounds includes information on critical human 
health end points, mode of action, pharmacokinetics, dose-response, and 
TEFs. There will be a total of nine chapters in Part II. Part III: 
Integrated Summary and Risk Characterization for 2,3,7,8-
Tetrachlorodibenzo-p-Dioxin (TCDD) and Related Compounds is intended to 
be a stand-alone document. In this part, key findings pertinent to 
understanding the potential hazards and risks of dioxins are described 
and integrated, including a discussion of all important assumptions and 
uncertainties.
    The two draft documents that are the subject of the independent 
scientific peer review meeting announced today are the new TEF chapter 
and the updated, revised, and reformatted Integrated Summary and Risk 
Characterization. The TEF chapter was developed as a result of a 
recommendation from the SAB to gather in one place the discussion and 
scientific information on the complex issue and use of TEFs for dioxin 
and dioxin-like compounds. The draft TEF chapter was developed by a 
team of experts and has undergone internal EPA review. The Integrated 
Summary and Risk Characterization, formerly identified as Chapter 9: 
Risk Characterization in the 1994 draft reassessment, was initially 
revised using a writing team process. The writing team was composed of 
approximately 12 leading scientific experts in fields related to dioxin 
exposure and health effects. These experts came from a wide range of 
public and private organizations, as well as academia. A preliminary 
revised draft was developed by a writing group and was reviewed by the 
40 individual stakeholders. This preliminary draft was used as the 
framework for an extensively revised document developed by a small 
internal EPA writing group.
    The third section of the reassessment on which the SAB recommended 
substantive revisions is Chapter 8: Dose-Response Modeling for 2,3,7,8-
TCDD. The draft Chapter 8 underwent public comment and external peer 
review in March 1997. A writing team developed the draft final chapter 
based on the peer review and public comments and any relevant new 
scientific data in January 2000. Because this section has already 
undergone extensive review, we are not soliciting further comments. The 
next step for Chapter 8 is SAB review in the Fall 2000.
    After the July 25 and 26 external peer review workshop, the TEF 
chapter and Integrated Summary and Risk Characterization will be 
revised to

[[Page 36900]]

reflect the comments of the independent scientific peer reviewers, 
other Federal agencies, and the public. In the Fall, the SAB will 
conduct a scientific peer review of the TEF chapter, the dose-response 
modeling chapter, and the Integrated Summary and Risk Characterization. 
The SAB review will be anounced in the Federal Register. EPA expects to 
conclude the dioxin reassessment about six months from now, 
incorporating appropriate changes that have been indicated by the 
comments of Federal agencies, the public, the external peer reviewers, 
and the SAB review panel. Final SAB approval is needed to produce a 
final EPA dioxin reassessment document.

    Dated: June 6, 2000.
Norine E. Noonan,
Assistant Administrator for Research and Development.
[FR Doc. 00-14853 Filed 6-9-00; 8:45 am]
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