Federal regulatory agencies have known for years the dangers that diacetyl exposure creates among workers in factories where bags of microwave popcorn are tested. The only agency to have taken any action, the U.S. Environmental Protection Agency (EPA), has kept its study of the chemical's impact on consumers secret except for sharing it with the popcorn industry. Now the first case of potential consumer illness from exposure to diacetyl has been documented.

Diacetyl is a flavoring added to many types of food, including artificial butter flavoring in microwave popcorn, and is in widespread use. The Food and Drug Administration (FDA) declared it safe for consumption, but the Project on Scientific Knowledge and Public Policy (SKAPP) at George Washington University's School of Public Health reports on its website that the

National Institute for Occupational Safety and Health (NIOSH) conducted several studies that confirmed the link between occupational exposure to artificial butter flavoring and lung diseases. In 2000, they issued recommendations to a Missouri microwave popcorn plant about protecting workers from this hazard, and in 2003, they sent an alert recommending safeguards to 4,000 businesses that might use or make butter flavoring.

According to a Seattle Post-Intelligencer article, there have been "scores of jury decisions and settlements awarding millions of dollars to workers who sued after having their lungs destroyed" by diacetyl exposure. These workers suffer from the debilitating lung disease bronchiolitis obliterans, or "popcorn workers lung."

The Occupational Safety and Health Administration (OSHA) has the authority to regulate workplace safety in this area but has not. On Sept. 7, a coalition of unions and public health experts wrote a letter to Secretary of Labor Elaine Chao urging her to push OSHA to issue an Emergency Temporary Standard for diacetyl and then follow with a regulation. It was the second letter the group sent to Chao, the first sent over a year ago. OSHA failed to take any action after the first letter.

The second letter urging OSHA to address the issue was prompted in part by a new revelation that "popcorn lung" had been discovered in a non-factory worker, a consumer who ate microwave popcorn at least twice a day, according to a Sept. 6 Chicago Tribune article. Dr. Cecile Rose, a lung specialist at the National Jewish Medical and Research Center in Denver, treated the patient and tested the levels of diacetyl fumes in his home while microwaving popcorn. "Peak levels of the fumes were similar to those measured in factories," the Tribune reported.

Rose wrote a letter in July to EPA, FDA, OSHA and the Centers for Disease Control and Prevention (CDC) about her patient and outlined the medical symptoms he experienced and their consistency with factory workers' clinical symptoms. SKAPP had petitioned FDA in September 2006 to remove diacetyl's "generally regarded as safe" status. Thus FDA and OSHA, the two agencies responsible for protecting consumers and workers, respectively, already knew the dangers from diacetyl exposure, and NIOSH (part of CDC) had confirmed the link between the lung disease and exposure.

The only agency that addressed the diacetyl issue was EPA, which conducts indoor air quality research. According to the Post-Intelligencer article, EPA began studying whether consumers were at risk in 2003 and finished its study last year. It still has not released the report, but it has circulated it to the popcorn industry for its review. The article states that George Gray, the head of EPA's Office of Research and Development, shared the report with the industry to assure it that none of industries' confidential information would be released to the public through the report. Gray also said the information could not be released publicly because it might prevent his scientists from getting their work published in peer reviewed journals.

The EPA denied a Freedom of Information Act request last fall from The Associated Press (AP) for the report, arguing it was a draft still under review. The agency has not yet answered an AP appeal of that rejection, according to a Sept. 5 article in the Washington Post. The Office of Management and Budget's 2004 Peer Review Bulletin allows agencies to exempt "time-sensitive medical, health, and safety determinations" from the peer review requirements. EPA has the discretion under the peer review guidelines, therefore, to release the information if it sees a public health benefit.

The Post-Intelligencer quotes Dr. David Michaels of SKAPP, and one of the signatories of the letter to Chao, as saying, "EPA cannot be permitted to play these games with matters that are important to public health. This is just questionable science at its worst."

Meanwhile, manufacturers of microwave popcorn have now begun to voluntarily remove diacetyl from their products, although they had the results of the EPA study in late 2005, according to the Washington Post story. ConAgra Foods, Inc., General Mills, Inc., the American Popcorn Company and Weaver Popcorn have started to phase out or replace the flavoring additive.