View PDF of News Release

September 12, 2006 – The Project on Scientific Knowledge and Public Policy (SKAPP) has petitioned the Food and Drug Administration (FDA) to revoke the “generally regarded as safe” (GRAS) designation for diacetyl, the artificial butter-flavoring chemical linked to severe lung illness in workers at microwave popcorn plants and other facilities.

Diacetyl received GRAS designation based on studies supplied by the flavor industry that showed diacetyl to be safe for ingestion. In recent years, the National Institute for Occupational Safety and Health (NIOSH) has identified numerous cases of lung disease — including the fatal illness bronchiolitis obliterans — and impairment among workers exposed to airborne diacetyl in food production plants. The FDA has not considered whether consumers face lung disease risks from inhaling diacetyl, a component of artificial butter flavor.

“There is compelling evidence that breathing diacetyl vapors causes lung disease, and there is no evidence of a safe exposure level,” explains SKAPP Director David Michaels, “so its wrong to classify it as ‘generally recognized as safe’.”

“We hope that research will show that consumers can safely prepare microwave popcorn in their homes,” Michaels says. “But until that research is conducted, diacetyl can’t legitimately retain its GRAS status.”

In July of 2006, two labor unions petitioned the Occupational Safety and Health Administration (OSHA) to issue an emergency temporary standard on diacetyl to protect workers in the food and flavorings industries. More than 42 scientists and public health experts signed a letter supporting the petition.

At the same time, SKAPP sent a letter to the Environmental Protection Agency (EPA) asking the agency to release a study it conducted more than two years ago on the chemicals released when consumers pop and open bags of microwave popcorn. The EPA responded that the paper summarizing their findings has undergone internal and external review and will be sent to industry “solely to ensure that no confidential business information is released”; the agency plans to submit the paper to a scientific journal this fall and anticipates publication by mid-2007.

The illness linked to diacetyl is often called “popcorn workers lung” because most of those diagnosed to date have worked in microwave popcorn factories. Two recent cases, however, have been diagnosed in workers at California plants that produce flavorings. NIOSH is now working with California state health officials to test the breathing capacity of current and former flavor workers, and labor unions have petitioned Cal-OSHA to set an emergency temporary standard for diacetyl.

Michaels stresses that diacetyl’s current inclusion on the GRAS list is symptomatic of a larger problem: “This is an example of a potentially toxic substance receiving GRAS designation without undergoing adequate testing. It’s also an example of how our key public health agencies rely on chemical manufacturers themselves to provide critical health effects data. Whether food additives, pesticides, or industrial chemicals, the public's health and safety should not rely solely on industry affirmations.”

Read more:
SKAPP's petition to the FDA and FDA's interim response
SKAPP's letter to the EPA and EPA's response
News release on petition to OSHA (HTML or PDF)
Background on diacetyl
Popcorn workers lung case study: Background on diacetyl studies, NIOSH investigation, and OSHA’s and EPA’s inadequate responses
Resources: Studies and other documents related to diacetyl
Links and resources from the California nonprofit WorkSafe