The announcement comes a week after Pop Weaver, the nation's second-largest popcorn producer, said it already had pulled the synthetic flavoring -- diacetyl -- from its microwave product delivered to stores last month.
Meanwhile, a lung specialist from Denver's National Jewish Medical and Research Center has notified federal agencies that she may have identified the first known case of a man who ate popcorn at home and had the same disease as the workers.
Lung specialist Dr. Cecile Rose wrote to the Food and Drug Administration, the Environmental Protection Agency, the Centers for Disease Control and Prevention and the Occupational Health and Safety Administration in July, advising them of her patient and the possibility that people who pop microwave corn at home can be at risk.
The rare lung disease that Rose diagnosed in her patient -- bronchiolitis obliterans -- can cause death in severe cases. Lung transplants are the only hope that patients have. The disease quickly leads to breathing difficulties and is often misidentified by physicians unfamiliar with the disease.