The world's largest producer of microwave popcorn, ConAgra Foods Inc., said yesterday that it plans to eliminate from its Orville Redenbacher and Act II brands a butter flavoring linked to severe lung disease in popcorn factory workers.
That announcement comes a week after Indianapolis-based Weaver Popcorn Co. said it had stopped using the same flavoring: diacetyl.
The companies' decisions coincide with the announcement by a doctor at a leading lung research hospital that a man who ate microwave popcorn daily might have developed the lung disease, which was previously thought to be limited to food plant workers.
The doctor and industry representatives emphasized that the man's illness had not been conclusively tied to microwave popcorn. The Food and Drug Administration said it was considering the case as part of a review of diacetyl's safety but was not aware of any other evidence that consumers were at risk from the flavoring.
Omaha, Neb.-based ConAgra made the decision in the past few months to phase out diacetyl to reduce risk to workers and alleviate consumer concerns, spokeswoman Stephanie Childs said.
"We fully acknowledge that there are consumer questions about it and its use," Childs said of diacetyl. "And we want to eliminate even the perception of risk."
The butter flavoring has been linked to bronchiolitis obliterans, a potentially deadly condition also known as "popcorn lung."
Federal scientists and other experts have determined in recent years that workers exposed to diacetyl were at risk of developing the condition. The Sun reported last year that workers in other food industry plants also might be at risk if they aren't protected from inhaling flavoring vapors.
In February, Dr. Cecile Rose, a lung specialist at National Jewish Medical and Research Center in Denver, determined that a man who ate microwave popcorn on a daily basis might have contracted bronchiolitis obliterans.
The man had difficulty breathing and a nagging cough, but doctors were mystified by the cause of his symptoms, said William Allstetter, a center spokesman.
The man was eventually referred to Rose, who has worked closely with the popcorn and flavoring industry on reducing workers' diacetyl exposure. She recognized that MRI images of the man's lungs showed abnormalities similar to those of bronchiolitis obliterans patients.
The man informed Rose he had eaten two bags of microwave popcorn a day for about 15 years, Allstetter said. In mid-July, Rose sent letters to several federal agencies noting the connection between the man's condition and his microwave popcorn habit.
"But we really want to emphasize this is one case," Allstetter said. "We are not completely certain the butter flavoring caused his condition."
While acknowledging a possible link between the man's illness and his popcorn consumption, John Hallagan, a spokesman for the Flavor and Extract Manufacturers Association of the United States, also cautioned against jumping to conclusions.
"We cannot be sure that the patient's exposure from the daily preparation of butter-flavored microwave popcorn caused the patient's illness," he said in a statement.
However, Hallagan added that the association is recommending that manufacturers of butter-flavored popcorn "consider reducing the diacetyl content of the flavors to the extent possible."
Diacetyl is a naturally occurring compound found in a number of products including butter, milk, cheese, fruits, wine and beer. Artificially produced forms of the flavoring are added to a variety of foods to give them a buttery flavor.
In 2002, federal scientists determined that fumes from the chemical were toxic when inhaled by workers in microwave popcorn plants.
Workers in plants that produce the butter flavoring have also contracted the illness, which can be so severe it necessitates a lung transplant. Several workers have died from lung illnesses linked to exposure to the chemical.
Critics say the federal government has not done enough to regulate diacetyl and has delayed releasing research on the safety of microwave popcorn.
In 2005, the Environmental Protection Agency completed a two-year study of fumes produced when microwave popcorn is prepared at home. Diacetyl was one of the compounds measured during popping and opening of the popcorn container.
Dr. George Gray, assistant administrator for the EPA's Office of Research and Development, said the study explored the amount and type of chemicals released and not the health effects of microwaving popcorn.
The study was made available to popcorn manufacturers after it was completed, but it has yet to be released to the public, according to EPA spokeswoman Suzanne Ackerman.
She said the delay was due to the time needed for scientific peer review and submission to a scientific journal. The research also required industry cooperation, she said, and part of the agreement was that companies got to see the report before it was published to ensure that no trade secrets were violated.
The study will probably be published this month in a "major scientific journal," Ackerman said, but she would not name the publication.
In the meantime, manufacturers are looking for alternative ways to add a buttery taste to the millions of bags of microwave popcorn eaten each year.
Weaver Popcorn, the nation's second-largest popcorn manufacturer, has reportedly discovered a new ingredient to provide butter flavor.
ConAgra's Childs said the company is still trying to develop an alternative flavoring and hopes to completely phase out diacetyl within a year.