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Environmental Assessment

IRIS Toxicological Review of 1,2,3-Trichloropropane (External Review Draft)

IRIS Toxicological Review of 1,2,3-Trichloropropane (External Review Draft)

Note: EPA has updated this document, but this version is provided as a courtesy to the public as a matter of public record.

Technical Information Staff
by phone at:   703-347-8561
by fax at:   703-347-8691
by email at:  nceadc.comment@epa.gov


[09/30/09] UPDATE: As per the new IRIS process, all comments received from federal agencies and White House offices on draft IRIS assessments will be made publicly available. Accordingly, interagency comments and the interagency draft of the 1,2,3-Trichloropropane IRIS assessment will be available on this website on or before October 14, 2009.

[1/18/08] EPA announced the External Peer Review Panel Meeting in a January 18, 2008 Federal Register Notice and includes the charge to external peer reviewers and the public (under downloads).

[11/16/07] EPA announced the release of the Toxicological Review of 1,2,3-Trichloropropane in the November 16, 2007 Federal Register Notice. This draft assessment is provided for public viewing and comment. Public comments received on the Toxicological Review within the external review period (next 60 days) will be provided to the peer reviewers prior to the meeting for their consideration. Any comments not received within the requested time period will be considered by EPA in their revisions.

EPA conducted a peer review of the scientific basis supporting the human health hazard and dose-response assessment of 1,2,3-trichloropropane (TCP) that once finalized will appear on the Integrated Risk Information System (IRIS) database. Peer review is meant to ensure that science is used credibly and appropriately in derivation of the dose-response assessments and toxicological characterization.
The draft Toxicological Review of 1,2,3-Trichloropropane provides scientific support and rationale for the hazard identification and dose-response assessment pertaining to chronic exposure to 1,2,3-trichloropropane. 1,2,3-Trichloropropane is an important industrial chemical used as a solvent for oils and fats, waxes, and resins, and has also been used in paint thinner and varnish remover and as a degreasing agent. 1,2,3-Trichloropropane is also generated as a by-product of the production of other chlorinated compounds such as epichlorohydrin, and is used as an intermediate in the production of some pesticides and polymers, such as polysulfide rubbers.

This assessment contains the derivation of a chronic reference dose and a chronic reference concentration, as well as a cancer characterization and the derivation of an oral slope factor.


2003EPA began reviewing the toxicological assessment of 1,2,3-trichloropropane.
Nov 2007EPA released an External Review Draft for public comment and review.
Jan 2008EPA announces the external peer review panel meeting in a Jan 18, 2008 Federal Register Notice.
Sep 2009EPA released the Final Toxicological Review (PDF) (247 pp, 1.9M) and accompanying Summary for 1,2,3-Trichloropropane to the IRIS Web site.

Next Steps

Following the public review and comment period, the draft Toxicological Review will be reviewed by an external expert peer review meeting, to be announced in a proceeding Federal Register Notice.

Downloads/Related Links

Additional Information

Comments on the assessment may be submitted and reviewed using the e-Government Regulations.gov Web site. From the site, select Environmental Protection Agency and the key word EPA- HQ-ORD-2007-1083 (for the docket ID).


U.S. EPA. IRIS Toxicological Review of 1,2,3-Trichloropropane (External Review Draft). U.S. Environmental Protection Agency, Washington, DC, NCEA-S-1669.

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