A total of 30 factory workers at the Jasper, Mo.-based popcorn maker Gilster Mary Lee have filed suits claiming lung damage from handling a butter flavoring ingredient, diacetyl, used in microwave-popcorn and other products.

Barred from suing their employer under workers' compensation law, factory workers have brought actions against International Flavors and Fragrances Inc., a New York-based manufacturer that has supplied the butter flavoring ingredient to the Gilster Mary Lee plant.

The latest jury verdict in the case involving four workers was returned June 28 in Jasper County Circuit Court in Carthage, Mo. It is the third case to come to trial involving Gilster Mary Lee workers.

During the first trial in March, the jury awarded a total of $20 million in damages to one factory employee and his wife. International Flavors and Fragrances said it has since appealed that verdict.

During a second trial involving another worker, a confidential settlement was reached before the jury could decide on the case. The latest verdict involving four workers leaves the cases of 24 more workers still to be disposed of.

"We believe that our ingredients are safe if they are used according to the safety instructions that we include with them. That's our feeling, basically," said a spokesperson from International Flavors & Fragrances.

"This is the only type of lawsuit in the country involving popcorn," the spokesperson told National Underwriter. She also noted that the ingredient in question, called diacetyl, is a naturally occurring substance that can be found in wine and cheeses.

The spokesperson noted that plaintiffs have been maintaining that they have developed a lung disease called bronchiolitis obliterans, which results in widespread obstructions of small airways. The spokesperson added, "We don't characterize any lawsuits as frivolous, but we stand by our belief that our ingredient is safe when used according to safety instructions."

"We still supply our ingredient to other popcorn manufacturing companies on a limited basis," she said, adding that her company has had no other complaints from any other clients. "Diacetyl is something that's been used in all kinds of food products for 50, 60 years. It's in other kinds of snack foods, too."

Plaintiffs, on the other hand, maintain that International Flavors & Fragrances knew about the dangers but didn't provide any warning.