Two right-wing, industry-backed groups filed a data quality petition with the U.S. Environmental Protection Agency (EPA) challenging the agency's labeling of certain chemicals as "likely human carcinogens." Specifically, the Washington Legal Foundation (WLF) and the American Council on Health and Science (ACHS) want EPA to eliminate statements in its Guidelines for Carcinogen Risk Assessment that indicate that a substance may properly be labeled as "likely to be carcinogenic to humans" based solely or primarily on the results of animal studies. Background EPA publishes and periodically revises a series of documents to assist risk assessors in evaluating the risks of environmental hazards; the Guidelines for Carcinogen Risk Assessment is one such document. The principle focus of the guidelines is hazard identification: can a chemical agent present a carcinogenic hazard to humans, and, if so, under what circumstances? The guidelines direct investigators to weigh all available evidence, briefly summarize the results of the risk analysis, and provide a conclusion with regard to carcinogenic risk to humans. The guidelines include lengthy discussions regarding the use of animal studies in making risk assessments and state that an agent may be labeled "likely to be carcinogenic to humans" based on a variety of evidence derived from animal studies. The Challengers The ACSH is a self-described "consumer education consortium concerned with issues related to food, nutrition, chemicals, pharmaceuticals, lifestyle, the environment and health." However, the group has been heavily funded by industry for years; among the past corporate contributors are numerous food, drug and chemical companies. According to the Center for Media & Democracy, the group has taken an "apologetic stance regarding virtually every... health and environmental hazard produced by modern industry." The WLF was founded in 1977 to "fight activist lawyers, regulators, and intrusive government agencies at the federal and state levels." The group has received sizable donations from the tobacco industry for its work opposing so called "junk science," which it claims has been used to establish the dangers of cigarettes. Request for Correction The August 23 data quality challenge objects to EPA's policy of erring on the side of caution in making its determinations. The Data Quality Act, passed by Congress in 2000, required that agencies establish guidelines to maximize the quality of their data and allow outside stakeholders to request a correction of any information they believe does not meet the guidelines. The WLF and ACSH claim that EPA is distorting scientific evidence with this policy, and they are requesting that a litany of specific corrections be made to the text of the guidelines. Among the "corrections" recommended is a request to replace an assertion that agency policy should be health protective with a statement that "no risk assessment procedures should be as decision-making tools." The petitioners also called for the deletion of an entire paragraph that explains that studies indicating a chemical to be an animal carcinogen may be used to assess a carcinogenic effect in humans, because the agency does not test carcinogens on humans. The sole evidence used in the data quality petition to challenge EPA's guidelines is a book written by the ACSH, entitled America's War on Carcinogens: Reassessing the Use of Animals Tests to Predict Human Cancer Risk. The book claims that the use of high-dose animal studies to determine human cancer risks is not scientifically sound. It further asserts that animal studies are often misinterpreted in a manner that distorts the risk to humans associated with exposure to such chemicals and that such studies confuse the public regarding cancer risks and actually undermine public health. The WLF and ACSH petition represents a new low in the misuse of the data quality challenge process, seizing upon the existence of scientific uncertainty and attempting to use the data quality guidelines to call data unreliable or poor. No scientific study or finding is ever certain, and EPA has established policies that it believes are ethical and scientifically sound. Because it does not test carcinogens on human subjects, the agency must make policy decisions based on the best available information -- animal studies. The challenge does not question the veracity of findings from any specific animal study, merely the use of these studies to assess the risk of cancer in humans. However, the manner in which the agency uses sound scientific information is a policy issue, not a data quality issue. The objections raised by WLF and ACSH in their data quality petition are clearly beyond the scope of the guidelines. This data quality challenge more than any other, is sound reason for re-evaluating its usefulness to agencies but more importantly, its usefulness to the public.