US EPA

Hexavalent chromium has been used historically in the chrome plating of metals, as an ingredient in dyes and pigments, in the leather tanning process, and as a wood preservative. It is often released into the environment following the disposal of chromium-containing materials or as a by-product of the processes that use this metal. EPA had determined some time ago that hexavalent chromium can cause cancer in humans when they are exposed to it by breathing, but until recently, little information was available regarding its potential to cause cancer in humans when ingested.

In September 2010, EPA released a draft IRIS assessment for hexavalent chromium, for the oral route of exposure only, for peer review and public comment. An independent expert peer review panel met in May 2011 to review the draft assessment. In their final report, the peer review panel urged EPA to consider the results of research that would soon be completed and peer-reviewed that could provide relevant scientific information that may inform the findings of the assessment.

EPA takes seriously its commitment to rigorous independent expert peer review. Based on the advice of the peer review panel, EPA will review original primary research related to the health effects of hexavalent chromium that has been published since the release of the draft assessment for external peer review and will incorporate the findings as appropriate into its hexavalent chromium assessment.

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 occurring 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, and ingesting food and drinking water containing chromium. Dermal exposure to chromium can occur from skin contact with certain consumer products or soils that contain chromium.

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.

This draft has been archived.

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