US EPA

On September 30, 2010, the draft Toxicological Review of Hexavalent Chromium and the charge to external peer reviewers were released 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 and the interagency science consultation draft of the IRIS Toxicological Review of Hexavalent Chromium and the charge to external peer reviewers are posted on this site.

The draft Toxicological Review of Hexavalent Chromium provides scientific support and rationale for the hazard and dose-response assessment pertaining to chronic exposure to hexavalent chromium via ingestion.

Chromium is a naturally occuring element in the earth's crust. The three main forms of chromium found in the environment are chromium (0), chromium (III), and chromium (VI), also known as hexavalent chromium. Chromium is widely used in manufacturing processes, and it can be found in many consumer products such as wood treated with copper dichromate, leather tanned with chromic sulfate, and stainless steel cookware. Chromium is released to the environment from natural and anthropogenic sources, with the largest releases occurring from industrial sources. The general population may be exposed to chromium by inhaling ambient air, ingesting food, and drinking water containing chromium. Dermal exposure of the general public to chromium can occur from skin contact with certain consumer products or soils that contain chromium.

EPA is undertaking a new health assessment for hexavalent chromium for the Integrated Risk Information System (IRIS). The outcome of this project will be a Toxicological Review and IRIS and IRIS Summary of hexavalent chromium that will be entered on the IRIS database. IRIS is an EPA database containing scientific information on potential adverse human health effects that may result from chronic (or lifetime) exposure to chemicals in the environment. IRIS contains chemical-specific summaries of qualitative and quantitative health information which can be combined with exposure assessment information to evaluate potential public health risks associated with environmental contaminants. The IRIS database is relied on for the development of risk assessments, site-specific environmental decisions, and rule making.

Following external peer review the draft report will be revised taking into consideration external peer review and public comments, will undergo a final EPA internal review and a review by a science discussion with other federal agencies and White House offices, and then will finally be posted to the IRIS Web site.

U.S. EPA. IRIS Toxicological Review of Hexavalent Chromium (2010 Interagency Science Consultation Draft). U.S. Environmental Protection Agency, Washington, DC, EPA/635/R-10/004C, 2010.