Last week, Pop Weaver announced that it was eliminating diacetyl from its microwave popcorn products. Today, the Seattle Post-Intelligencer and Associated Press report that ConAgra will remove diacetyl from its Orville Redenbacher and Act II microwave popcorn over the next year. This news comes as David Michaels’s post here about federal agencies’ inadequate response to a case of bronchiolitis obliterans in a popcorn consumer has attracted widespread media attention (e.g., from the Associated Press, Denver Post, and Milwaukee Journal-Sentinel).

It’s great to see that popcorn companies are responding to the problem of diacetyl, since federal agencies are reacting slowly and ineffectually. These announcements still prompt us to ask something we’ve asked before, though: What do Pop Weaver and ConAgra know about diacetyl exposure that the public doesn’t?

In particular, we’re concerned because it seems that the EPA has shared with ConAgra and Pop Weaver results of a study it conducted to measure the emissions from microwave popcorn. (The study does not deal with health effects related to the emissions, but it should be possible to compare emissions data with diacetyl measurements from manufacturing facilities where workers diagnosed with bronchiolitis obliterans were employed.) In a Seattle Post-Intelligencer article about Pop Weaver’s decision to drop diacetyl from its products, Andrew Schneider reports:

In part, it was the EPA’s study that led Pop Weaver to reformulate its flavoring without diacetyl, said Mike Weaver, chief executive officer of the 80-yearold family-owned company.

Back in May, David Michaels reported on a 2004 letter from a Senior VP at ConAgra to EPA’s Assistant Administrator for the Office of Research and Development. The letter indicated not only that ConAgra knew about EPA’s research on diacetyl emissions but that the company had been conducting its own research and had developed a “Consumer Exposure Risk Index for butter flavors in microwave popcorn.”

So, why hasn’t the EPA shared the results of its study with the public? Andrew Schneider checked into the agency’s excuse:

But the industry already knows what the EPA found, according to George Gray, the current head of the EPA’s office of Research and Development. He told the P-I that the popcorn industry was given the opportunity to review the final results before the study was submitted for publication.

Gray said there was nothing improper in allowing the industry to review the findings, saying it was necessary to convince industry that none of their confidential business information, such as what the flavoring agents are and the construction of the popping bag, was released to the public.

Further, Gray said the information could not be released to other public health professionals because it would prevent his scientists from getting their work published in peer-reviewed journals.

However, most prominent medical and scientific journals said that exceptions are always made.

“We’re not going to punish researchers for disclosing information that is of vital interest to the public health,” said Karen Pedersen, manager of media relations for The New England Journal of Medicine.

Now that a case of bronchiolitis obliterans has been identified in a microwave popcorn consumer, even more people are concerned about their exposure to this widely consumed snack food. The EPA should release the results of its study immediately and show that at least one federal agency is capable of doing the right thing for public health.

Liz Borkowski works for the Project on Scientific Knowledge and Public Policy (SKAPP) at George Washington University’s School of Public Health and Health Services.