A man who filed a lawsuit claiming he suffered lung damage after being exposed to a chemical used in a buttery flavoring for microwave popcorn has reached a settlement with the company that made the flavoring.

John Weimer Jr., of Wall Lake, had filed a lawsuit against International Flavors & Fragrances Inc., claiming the New York-based company was negligent.

Weimer claimed his lungs were damaged by exposure to diacetyl, a chemical linked to a respiratory disease known as popcorn lung, while he worked as a manager at the Snappy Popcorn Company plant in Breda, Iowa.

Weimer's attorney, Kenneth McClain, of Independence, Mo., said the settlement contained a provision prohibiting either side from discussing its terms. Trial had been scheduled to start next week.

"We're pleased it was settled and fortunate we were able to resolve it without trial," McClain said.

McClain said Weimer's breathing capacity is about half what it should be.

In the lawsuit, filed in 2005 in U.S. District Court, Weimer claimed International Flavors & Fragrance knew of the health hazard associated with the flavoring but failed to warn users and medical and government agencies.

The National Institute of Health has linked exposure of vapors from butter flavoring to lung damage in popcorn plant workers. Health investigators have determined that the flavorings pose no danger to people who eat microwave popcorn.

Snappy Popcorn, which was not named in the lawsuit, no longer uses the product, owner Jon Tiefenthaler said.

Last fall, Kevin Remmes, an American Pop Corn worker in Sioux City, settled a similar suit for an undisclosed amount.

Ronald Kuiper, another American Pop Corn employee, has made similar allegations in a third lawsuit, which is scheduled for trial in November.

American Pop Corn is not named in either lawsuit.