external review draft" of their Toxicological Review of Hexavalent Chromium. EPA is conducting a peer review of the scientific basis supporting the human health hazard and dose-response assessment of hexavalent chromium, also called "chromium VI" or simply "Cr(VI)," so that it can be posted on EPA's Integrated Risk Information System (IRIS) database. While the water insoluble forms of chromium (e.g., chromium(III)) and chromium metal are not considered a health hazard, the toxicity and carcinogenic properties of chromium(VI) have been known for a long time.
Primarily the concern is related to chronic exposure to hexavalent chromium via ingestion. But EPA also looked at how much "the general population may be exposed to chromium by inhaling ambient air, and ingesting food and drinking water containing chromium." EPA also says that "dermal exposure to chromium can occur from skin contact with certain consumer products or soils that contain chromium."
The deadline for comments is November 29, 2010.
Industry representatives indicate that while they support "a comprehensive risk assessment," they wonder "why EPA feels it is necessary to act now, rather than wait to review the Cr(VI) studies underway." These additional studies are expected to be completed in early 2011.
A PDF of the Draft Toxicological Review can be downloaded on the EPA web site.