EPA announced the release of the Toxicological Review of Hexavalent Chromium in the September 30, 2010, Federal Register. This draft assessment is provided for public viewing and comment. Public comments received on the Toxicological Review during the public comment period will be provided to the external peer reviewers for their consideration. Any comments not received within the requested time period will be considered by EPA in their revisions. The deadline for comments is December 29, 2010.
EPA is conducting a peer review of the scientific basis supporting the human health hazard and dose-response assessment of hexavalent chromium that will appear on the Integrated Risk Information System (IRIS) database.
Background
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.
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.
History/Chronology
| Sep 1998 | The oral RfD for hexavalent chromium was posted to the IRIS database. The inhalation RfC for hexavalent chromium and the carcinogenicity assessment for hexavalent chromium were also posted to the IRIS database. |
| May 2010 | EPA initiated an interagency science consultation to review the draft toxicological review and charge to external peer reviewers. |
| Sep 2010 | EPA released the external review draft for public review and comment and the interagency science consultation review draft with comments. EPA also announced a public listening session to be held on November 18, 2010. [Federal Register Sep 30, 2010] |
| Nov 2010 |
Next Steps
Following the conclusion of the public review and comment period, public listening session, and external peer review, the draft Toxicological Review will be revised and submitted for a final Agency review and an EPA-led Interagency Science Discussion. As a last step, the final assessment will be posted on the IRIS database.
Downloads
· Toxicological Review of Chromium VI: in Support of Summary Information on the Integrated Risk Information System (IRIS) (PDF) (298 pp, 2 MB, about PDF)
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 keyword “EPA-HQ-ORD-2010-0540” (for the docket ID) to comment on this report.
Citation
U.S. EPA. IRIS Toxicological Review of Hexavalent Chromium (External Review Draft). U.S. Environmental Protection Agency, Washington, DC, EPA/635/R-10/004A, 2010.
California Office of Environmental Health Hazard Assessment (OEHHA), which supports a proposed Public Health Goal (PHG) of 0.06 parts per billion (ppb) in drinking water.
Delay
Industry groups, American Chemistry Council (ACC) has requested a delay in implementation. ACC requested even more studies to determine whether CR6 is indeed safe.
Some have indicated that the chromium industry have withheld data concerning the safety of CR6. Experts have already confirmed that CR6 is very dangerous to humans, “Faced with the threat of stronger regulation, the chromium industry initiated an effort to challenge the scientific evidence supporting a more protective [OSHA workplace] standard [for inhalation]. This effort included the use of “product defense” consultants [Exponent and ChemRisk] to conduct post hoc analyses of a publicly-funded study to challenge results viewed unfavorably by the industry” (Michaels et al, 2006). Recent reports have indicated that US troops have allegedly become sickened from exposure to CR6 in Iraq and Afghanistan from burn pit exposures.
There appears to be no valid reason to delay further the implementation of CR6 safety standards by EPA.
