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Draft Toxicological Review of Dichlorobenzenes: In Support of Summary Information on the Integrated Risk Information System (IRIS)

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Information about this document as published in the Federal Register.

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This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

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Environmental Protection Agency (EPA).


Notice of Extension of Public Comment Period, Rescheduled External Peer Review Panel Meeting, and Meeting Format Change.


The EPA is extending the public comment period and rescheduling an external peer review panel meeting to review selected sections of the EPA National Center for Environmental Assessment (NCEA) final draft document titled, “Toxicological Review of Dichlorobenzenes: In Support of Summary Information on the Integrated Risk Information System (IRIS)” (EPA/635/R-03/015), regarding the inhalation reference concentration (RfC) and inhalation cancer assessment for 1,4-dichlorobenzene. The EPA is also changing the format of this external peer review meeting to include both a teleconference and an in-person panel meeting.

On July 11, 2006, EPA published a Federal Register notice (71 FR 39113) announcing a comment period that ended August 9 and an external peer review panel meeting (by teleconference) that was scheduled for August 16. On August 11, 2006, EPA published a second Federal Register notice announcing an extension of the public comment period to October 10 and a rescheduling of the external peer review meeting to October 30. EPA is extending the public comment period to October 17, 2006, rescheduling the external peer review meeting to November 3, 2006, and changing the format to include both a face-to-face meeting and a teleconference option for participation. This extended public comment period and change in format for the external peer review are in response to requests from the public.

The public comment period and the external peer review meeting are separate processes that provide opportunities for all interested parties to comment on the document. In addition to consideration by EPA, all public comments submitted in accordance with this notice will also be forwarded to EPA's contractor, the Oak Ridge Institute for Science and Education (ORISE), for consideration by the external peer review panel prior to the meeting.

As previously stated in 71 FR 39113 and 71 FR 46220, EPA is releasing this draft document solely for the purpose of pre-dissemination peer review under applicable information quality guidelines. This document has not been formally disseminated by EPA. It does not represent and should not be construed to represent any Agency policy or determination.

ORISE invites the public to register to attend this peer review panel meeting as observers, either in person or by telephone. In addition, ORISE invites the public to give brief oral comments at the meeting regarding the draft document under review. The draft document and EPA's peer review charge are available via the Internet on NCEA's home page under the Recent Additions menu at​ncea. When finalizing this draft report, EPA will consider ORISE's report of the comments and recommendations from the external peer reviewers and any public comments that EPA receives in accordance with this notice.


The period for submission of comments on the final draft document will end on October 17, 2006. Technical Start Printed Page 60140comments should be in writing and must be received by EPA by October 17, 2006. Comments submitted to the EPA by October 17, 2006, will be provided to the external peer review panel prior to the panel review meeting. The peer review will be on November 3, 2006, and will begin at 9 a.m. and end approximately at 1 p.m., eastern time.


The external peer review panel meeting will be held at the American Geophysical Union, 2000 Florida Avenue, NW., Washington, DC 20009-1277. Under an Interagency Agreement between EPA and the Department of Energy, the Oak Ridge Institute of Science and Education (ORISE) is organizing, convening, and conducting the peer review panel meeting. To attend the meeting, register by October 17, 2006, by calling ORISE at (865) 576-2922, sending a facsimile to (865) 241-3168, or sending an e-mail to Margaret Lyday at Interested parties may also register via the Internet at​dichlorobenzene. You must register by October 17, 2006, if you wish to provide brief oral comments or if you plan to use the teleconference option at the peer review panel meeting.

The draft “Toxicological Review of Dichlorobenzenes: In Support of Summary Information on the Integrated Risk Information System (IRIS)” (EPA/635/R-03/015) is available primarily via the Internet on NCEA's home page under the Recent Additions menu at​ncea. A limited number of paper copies are available by contacting the IRIS Hotline at (202) 566-1676, (202) 566-1749 (facsimile), or If you are requesting a paper copy, please provide your name, mailing address, the document title, and the EPA number of the requested publication. Copies are not available from ORISE.

Copies of the study by Aiso et al. (2005), referenced in the SUPPLEMENTARY INFORMATION section of this notice, are available from the IRIS Hotline in paper or electronic format or via the docket at If you are requesting a copy from the IRIS Hotline, please provide your name, mailing address or e-mail address, and document citation: Aiso et al. (2005) Carcinogenicity and chronic toxicity in mice and rats exposed by inhalation to parA-dichlorobenzene for two years. J Vet Med Sci 67(10):1019-1029. EPA is providing this study in the interest of transparency. EPA is not endorsing or supporting the study or its findings.

Technical comments may be submitted electronically via, by mail, by facsimile, or by hand delivery/courier. Please follow the detailed instructions provided in the SUPPLEMENTARY INFORMATION section of this notice.

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Questions regarding registration and logistics for the external peer review panel meeting and teleconference should be directed to Margaret Lyday, ORISE, P.O. Box 117, MS 17, Oak Ridge, TN 37831-0117, at (865) 576-2922, (865) 241-3168 (facsimile), or (e-mail).

If you have questions about the document, contact Audrey Galizia, Chemical Manager, National Center for Environmental Assessment; telephone: (732) 906-6887; facsimile: (732) 452-6429; e-mail:

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I. Information About the Document

IRIS is a database that contains Agency scientific positions on potential adverse human health effects that may result from chronic (or lifetime) exposure to specific chemical substances found in the environment. The database (available on the Internet at​iris) contains qualitative and quantitative health effects information for more than 500 chemical substances that may be used to support the first two steps (hazard identification and dose-response evaluation) of the risk assessment process. When supported by available data, the database can be used as a resource for oral reference doses (RfDs) and inhalation reference concentrations (RfCs) for chronic health effects, and oral slope factors and inhalation unit risks for carcinogenic effects. Combined with specific exposure information, government and private entities use IRIS to help characterize public health risks of chemical substances in a site-specific situation and thereby support risk management decisions designed to protect public health.

1,4-Dichlorobenzene is widely used as a space deodorant for toilets and refuse containers, as a moth repellent in moth balls or crystals, and in other pesticide applications. The current IRIS assessment for 1,4-dichlorobenzene was placed on the database in 1994 and contains an inhalation RfC. A reassessment of the potential health effects of dichlorobenzenes has been undertaken. The draft assessment for dichlorobenzenes (including the 1,2-, 1,3-, and 1,4-isomers) was subject to an external peer review and 30-day public comment period in February 2004 (69 FR 4514, January 30, 2004). The scope of the current external peer review and public comment is limited to the analyses based on a chronic inhalation bioassay of 1,4-dichlorobenzene published in the peer-reviewed literature (Aiso et al., 2005. J Vet Med Sci 67(10):1019-29) that was not included in the February 2004 external peer review draft. This study was identified originally as an unpublished study report by the Japan Bioassay Research Center (JBRC, 1995). Data from Aiso et al. (2005) were used subsequently in the quantitative dose-response assessments for the 1,4-dichlorobenzene RfC and inhalation cancer assessment.

II. Panel Meeting Information

Members of the public may attend the panel meeting as observers, and there will be a limited time for comments from the public. To make oral comments at the commencement of the peer review meeting, you must pre-register with ORISE indicating your intent to do so. Space is limited, and reservations will be accepted on a first-come, first-served basis.

III. How to Submit Technical Comments to the Docket at


The EPA Docket Center suffered damage due to flooding during the last week of June 2006. The Docket Center is continuing to operate. However, during the cleanup, there will be temporary changes to Docket Center telephone numbers, addresses, and hours of operation for people who wish to make hand deliveries or visit the Public Reading Room to view documents. Consult EPA's Federal Register notice at 71 FR 38147 (July 5, 2006) or the EPA Web site at​epahome/​dockets.htm for current information on docket operations, locations and telephone numbers. The Docket Center's mailing address for U.S. mail and the procedure for submitting comments to are not affected by the flooding and will remain the same.

Submit your comments, identified by Docket ID No. EPA-HQ-ORD 2004-0002 by one of the following methods:

  • Follow the on-line instructions for submitting comments.
  • E-mail:
  • Mail: Office of Environmental Information (OEI) Docket (Mail Code: 2822T), U.S. Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460. The phone number is (202) 566-1752.
  • Hand Delivery: The OEI Docket is located in the EPA Headquarters Docket Center, EPA West Building, 1301 Constitution Ave., NW., Washington, DC. The EPA Docket Center Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The telephone Start Printed Page 60141number for the Public Reading Room is (202) 566-1744. Such deliveries are only accepted during the docket's normal hours of operation, and special arrangements should be made for deliveries of boxed information.

If you provide comments by mail or hand delivery, 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.

Instructions: Direct your comments to Docket ID No. EPA-HQ-ORD-2004-0002. EPA's policy is that all comments received will be included in the public docket without change and may be made available online at, including any personal information provided, unless the comment includes information claimed to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Do not submit information that you consider to be CBI or otherwise protected through or e-mail. The Web site is an “anonymous access” system, which means EPA will not know your identity or contact information unless you provide it in the body of your comment. If you send an e-mail comment directly to EPA without going through, your e-mail address will be automatically captured and included as part of the comment that is placed in the public docket and made available on the Internet. If you submit an electronic comment, EPA recommends that you include your name and other contact information in the body of your comment and with any disk or CD-ROM you submit. If EPA cannot read your comment due to technical difficulties and cannot contact you for clarification, EPA may not be able to consider your comment. Electronic files should avoid the use of special characters, any form of encryption, and be free of any defects or viruses. For additional information about EPA's public docket visit the EPA Docket Center homepage at​epahome/​dockets.htm.

Docket: All documents in the docket are listed in the index. Although listed in the index, some information is not publicly available, e.g., CBI or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, will be publicly available only in hard copy. Publicly available docket materials are available either electronically in or in hard copy at the OEI Docket in the EPA Headquarters Docket Center.

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Dated: October 5, 2006.

Peter W. Preuss,

Director, National Center for Environmental Assessment.

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[FR Doc. E6-16925 Filed 10-11-06; 8:45 am]