In comments submitted on a final draft toxicological review, the U.S. Department of Defense (DOD) has apparently warned the Environmental Protection Agency (EPA) that its August 11, 2010, Integrated Risk Information System assessment for 1,4 dioxane is vulnerable to a Data Quality Act (DQA) challenge. The department has specifically faulted EPA for using a carcinogenicity study that was revised and republished “after completion of the interagency and external peer reviews.” According to DOD, the changes included “the number of animals, the number of animals that had tumors, the doses given to the animals, and changes in both the statistical procedures and … calculations.”  

EPA has dismissed these alterations as “minor” and noted that it added text to the final risk assessment to clarify “which report … was the source for the data discussed.” The agency concluded that 1,4 dioxane, which is used as a solvent, cleaning agent, chemical stabilizer, surface coating, adhesive agent, and an ingredient in chemical manufacture, is “likely” to cause cancer in humans, an assessment that has apparently attracted much criticism from industry. As the Alliance for Environmental Responsibility and Openness (AERO) reportedly argued, the only studies linking 1,4 dioxane to tumors “are very high dose rodent studies.”  

Meanwhile, one media source has noted that a recent appellate ruling could open the floodgates for more DQA challenges. “While critics say the D.C. Circuit ruling does not set any new precedent, supporters have already filed a flurry of petitions challenging data EPA relied on in chemical risk assessments of key chemicals like methanol, arsenic and phthalates, as well as climate change, coal ash and other decisions,” states an August 23, 2010, Inside EPA article. “The dioxane petition could also be ripe for a data quality challenge given long-standing industry opposition.” When the DQA was enacted in 2001, it was widely expected to give industry interests a tool for slowing down regulatory processes and has reportedly been used by corporate and consumer interests to challenge the accuracy of agency information.