By Jack Schatz
The American Chemistry Council (ACC) is attacking a proposed rule to eliminate an exemption in the Proposition 65 listing of hexavalent chromium. The trade group is arguing that the agency should reconsider its action based on a new industry-funded study that downplays the health effects of the chemical.
The Office of Environmental Health Hazard Assessment (OEHHA) says it will review the studies submitted by industry representatives, but is defending its proposed amendment to the listing and its recently published Public Health Goal (PHG) for hexavalent chromium. OEHHA said in a letter responding to ACC, that the PHG is “based on sound science and is one of the most scientifically scrutinized documents in the history of the agency.”
At issue is a proposed rulemaking action, announced by OEHHA on Sept. 16, to amend Proposition 65 regulations to remove references to hexavalent chromium as posing no significant risk when ingested. According to the agency announcement, the action is based on recent scientific findings that establish that hexavalent chromium can be carcinogenic when ingested.
OEHHA is relying on its PHG document as the basis for the amendment to its listing of hexavalent chromium.
But ACC contends that OEHHA’s conclusions in the PHG were not scientifically sound, and the agency should use the new industry-funded research to develop a new public health goal.
ACC expressed disappointment with OEHHA’s decision to finalize its PHG for hexavalent chromium on July 27, two days after ACC staff briefed agency scientists on preliminary findings of the trade organization’s comprehensive study supporting the industry’s position.
ACC spokeswoman Ann Mason asserted that OEHHA should have waited for ACC to publish its research and review its study before finalizing its PHG, in a letter to OEHHA acting director, George Alexeeff, Ph.D., D.A.B.T., dated Sept. 8.
“The findings from a major, peer-reviewed research project, scheduled for release in the next few months, will provide the information OEHHA needs to establish a responsible and science-based drinking water standard for hexavalent chromium,” Mason wrote. “We strongly encourage the agency to base its standards on those findings.”
Mason noted that earlier this year nine independent experts reviewed and commented on an EPA draft toxicological review for oral exposures to hexavalent chromium. Several peer reviewers expressed a number of significant concerns about the scientific quality of the draft review and suggested ways to correct errors and fill in missing data, Mason wrote.
“In light of the comments from these hexavalent chromium experts, it is troubling that OEHHA finalized the PHG knowing that, within month, the MOA study will provide important scientific information central to the State of California’s ability to accurately assess the potential human health risks associated with oral exposure to hexavalent chromium.”
Mason closed by noting that “the public interest is best served when the weight of scientific evidence is used to inform regulatory decisions. OEHHA’s decision to adopt the PHG, knowing that the results of the MOA study are imminent, suggests that OEHHA is pre-disposed to dismissing an extensive body of pathology, bio-chemistry, genomics, and pharmacokinetics that should inform the final PHG. We sincerely hope this is not the case, and hope that OEHHA will fulfill its written commitment to consider the enormous amount of forthcoming data, and revise the PHG accordingly in 2012.”
But in a Sept. 23 letter to ACC, Alexeeff defended OEHHA’s work on hexavalent chromium and disputes assertions by ACC that OEHHA should have waited for publication of the “ACC-funded study” before publishing the PHG.
Alexeeff noted that the PHG “document was subject to two public comment periods, and, unusually, two separate peer reviews overseen by the University of California involving a total of eight expert scientists. The document cites over 50 experiments that found hexavalent chromium causes genetic damage, including the 2008 study by the National Toxicology Program (NTP) that determined that CrVI in drinking water was carcinogenic in standard two-year bioassays in rats and mice (NTP, 2008).”
Alexeeff also observed that hexavalent chromium remains a common contaminant in California water supplies, having been detected in 2,207 of approximately 12,000 water sources.
“While we remain very interested in the ACC study, we do not think that the interests of public health would have been very well served by indefinitely delaying the finalization of the PHG and thereby delaying the California Department of Public Health’s ability to directly regulate CrVI in drinking water supplied to a significant number of Californians,” Alexeeff wrote.
In closing, Alexeeff said that OEHHA has followed the progress of the ACC-funded study, and found some of the preliminary data “useful.” But he also observed that none of the data counters the central findings of OEHHA’s PHG document—exposure to hexavalent chromium via drinking water causes cancer through a genotoxic mode of action at low exposure concentrations.
Since Dr. Alexeeff sent his response to ACC, the organization, along with the California Manufacturers and Technology Association have requested an extension of the public comment period, which was granted by OEHHA. The agency will now accept public comments on the amended NSRL for hexavalent chromium through November 30, 2011.
Written comments, along with any supporting documentation, may be transmitted via email addressed to Fran.Kammerer@oehha.ca.gov or to:
Office of Environmental Health Hazard Assessment
Street Address: 1001 I Street, 23rd Floor
Sacramento, California 95814
Mailing Address: P.O. Box 4010
Sacramento, California 95812-4010
Fax No.: (916) 323-2517 Telephone: (916) 445-4693