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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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Environmental Protection Agency (EPA).


Notice of Public Comment Period and External Peer Review Panel Meeting.


The EPA is announcing a public comment period and an external peer review panel meeting to review selected sections of the final draft document titled, “Toxicological Review of Dichlorobenzenes: In Support of Summary Information on the Integrated Risk Information System (IRIS)” (EPA/Start Printed Page 39114635/R-03/015), related to the inhalation reference concentration (RfC) and inhalation cancer assessment for 1,4-dichlorobenzene. The document was prepared by the National Center for Environmental Assessment (NCEA) within EPA's Office of Research and Development.

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. EPA will consider any public comments submitted in accordance with this notice when revising the document.


The public comment period begins on July 11, 2006 and ends August 9, 2006. Technical comments should be in writing and must be received by EPA by August 9, 2006. The peer review panel meeting will be conducted on August 16, 2006 by teleconference and will begin at 1 p.m. and end at 4 p.m. Members of the public may call into the teleconference meeting and are invited to provide oral statements at the commencement of the teleconference. (For more information refer to the instructions for registration provided in the ADDRESSES section of this notice.)


The external peer review panel meeting will be held by teleconference. 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 obtain the teleconference call-in number and access code, register by August 11, 2006, by calling ORISE, P.O. Box 117, MS 17, Oak Ridge, TN 37831-0117, at (865) 576-2922 or (865) 241-3168 (facsimile). Interested parties may also register on-line at:​dichlorobenzene. Public comments submitted to the EPA by August 9, 2006 will be provided to the external peer review panel prior to the teleconference 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. If you are requesting a copy, please provide your name, mailing address or email 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.

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 teleconference should be directed to Margaret Lyday, ORISE, P.O. Box 117, MS 17, Oak Ridge, TN 37831-0117, at (865) 576-2922 or (865) 241-3168 (facsimile), (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 scientific Agency 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 provides 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. How To Submit Technical Comments to the Docket at

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

  • Follow the online instructions for submitting comments.
  • E-mail:
  • Fax: 202-566-1753.
  • 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, Room B102, 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 number 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 in writing, please submit one unbound original with pages numbered consecutively, and three copies of the comments. For Start Printed Page 39115attachments, 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: July 5, 2006.

Peter W. Preuss,

Director, National Center for Environmental Assessment.

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[FR Doc. E6-10870 Filed 7-10-06; 8:45 am]