US EPA

On September 9, 2011, the Toxicological Review of 1,4-Dioxane (with inhalation update) (External Review Draft) was posted for external peer review and public comment. The Toxicological Review and charge were reviewed internally by EPA and by other federal agencies and White House Offices before public release. In the new IRIS process, introduced by the EPA Administrator, all written comments on IRIS assessments submitted by other federal agencies and White House Offices will be made publicly available. Accordingly, interagency comments with EPA's response and the interagency science consultation draft of the IRIS Toxicological Review of 1,4-dioxane and the charge to external peer reviewers are posted on this site.

1,4-Dioxane is commonly used as a solvent, cleaning agent, chemical stabilizer, surface coating, adhesive agent, and an ingredient in chemical manufacture. The IRIS Program completed the assessment for oral exposure to 1,4-dioxane on August 11, 2010 and noted that new inhalation studies would be evaluated separately. Additional information regarding 1,4-dioxane toxicity resulting from exposure via inhalation has now been incorporated into the 2010 assessment without changing the oral toxicity conclusions of the previous assessment.

The Toxicological Review of 1,4-dioxane provides scientific support and rationale for the hazard and dose-response assessment pertaining to chronic exposure to 1,4-dioxane.

Following external peer review the assessment will be revised taking into consideration external peer review and public comments. The revised assessment will undergo a final EPA internal review and review by other federal agencies and White House offices, then the final assessment will be posted to the IRIS database.

U.S. EPA. IRIS Toxicological Review of 1,4-Dioxane (Interagency Science Consultation Draft). U.S. Environmental Protection Agency, Washington, DC, EPA/635/R-11/003C, 2011.