You'd better think twice before cranking up the microwave and sniffing the aroma from a freshly opened bag of popcorn. Environmental agencies are currently embroiled in an interesting jurisdictional overlap, at the federal and state level, over my favorite sports-viewing snack. The conflict is between the Food and Drug Administration (FDA), the Environmental Protection Agency (EPA), and the National Institute for Occupational Health and Safety (NIOSH) of the Occupational Health and Safety Admistration (OSHA). The problem involves dozens of workers around the US who have developed a debilitating lung disease called bronchiolitis obliterans, otherwise known as “popcorn worker's lung”, and other respiratory diseases, from exposure to fumes from the artificial butter flavoring, diacetyl, in microwave popcorn. The EPA regulates hazardous ambient air pollutants through the Clean Air Act (CAA) and the manufacture and distribution of imminently hazardous chemical substances under the Toxic Substances Control Act (TSCA), while OSHA is responsible for the regulation of airborne contaminants in the workplace. To add salt to the popcorn wound, the FDA governs food additives, of which diacetyl is one, and while it considers the chemical safe as an edible product, the problem lies with the form of exposure. Consumer inhalation does not fall under the jurisdiction of any of these agencies. In the 1990s, NIOSH conducted several studies that confirmed the link between occupational exposure to artificial butter flavoring and lung disease. In 2000, NIOSH issued recommendations to a Missouri microwave popcorn plant about protecting workers from this hazard, and in 2003 they sent an alert, recommending safeguards, to 4000 companies that might use or make butter flavoring. In the much larger food processing industry, however, tens of thousands of workers are estimated to work with such flavorings. In March of this year, California Assemblywoman Sally Lieber introduced a bill that would ban diacetyl in the state's workplace by 2010, and Cal-OSHA drafted a standard on occupational exposure to food flavorings. But the FDA remains stubborn – FDA Commissioner Von Eschenbach responded to a Congressional inquiry in May 2007 that “the agency does not have evidence that would cause it to take immediate action with respect to diacetyl” and that it will continue to monitor the issue. Citing OSHA's unwillingness to act, Representatives Lynn Woolsey and George Miller introduced in June of this year legislation that would require OSHA to set an interim and final standard for occupational exposure to diacetyl. The EPA has made a study of the harmful effects of breathing diacetyl fumes, but it is not yet public. One may, however, draw conclusions from the fact that at least one manufacturer of microwave popcorn announced it was reformulating its flavorings to eliminate diacetyl. Three months ago, Cecile Rose, an expert in occupational and environmental medicine at Denver's National Jewish Medical and Research Center, wrote to the FDA, the Centers for Disease Control and Prevention (CDC), the EPA, and OSHA, informing the agencies about a patient “with significant lung disease, whose clinical findings are similar to those described in affected workers, but whose only inhalational exposure is as a heavy, daily consumer of butter-flavored microwave popcorn”. While it is impossible to make sweeping judgments based on one case, the response to Rose is worrisome. The FDA simply isn't buying this as a reason for taking diacetyl off the GRAS list, while the EPA has undertaken a study of the inhalation effects and has apparently shared it with popcorn companies, but hasn't released the information publicly. The CDC reportedly didn't respond to Rose's inquiry at all. Perhaps OSHA will respond to Congressional action, but they are not charged with responsibility to consumers. Maybe the microwave popcorn and flavorings industries have indeed gotten the message. The flavoring manufacturers' trade association, known by the unfortunate acronym “FEMA”, stated: “out of an abundance of caution, FEMA recommends that its members who manufacture butter flavors containing diacetyl for use in microwave popcorn consider reducing the diacetyl content of these flavors to the extent possible”. Hopefully, some agency will solve this problem soon, because I've got a tense pro football season to deal with.