Dozens of plant workers who claim their health was damaged by exposure to a chemical used to give a buttery flavor to microwave popcorn have filed lawsuits in Cincinnati against makers of the flavoring. At least 43 workers filed lawsuits claiming their lungs were irreversibly damaged by inhaling fumes from the chemical diacetyl, which provides the buttery taste. Some work at a local plant of Cincinnati-based Givaudan Flavors Corp. Many others are from a plant in Marion owned by Omaha, Neb.-based ConAgra Foods.

Givaudan supplies flavorings to food manufacturers, including popcorn makers. ConAgra and other leading makers of microwave popcorn removed the flavoring chemical from their products after it was linked to cases of bronchiolitis obliterans, a rare life-threatening disease often referred to as "popcorn lung." Donald Powell of Burlington, Ky., worked at Givaudan for 18 years beginning in 1985. Powell, who was a chemical operator, suffers from severe lung damage and has trouble breathing, according to the lawsuit he filed in Hamilton County Common Pleas Court in November. His lawsuit, and one filed by Paul Dunbar of Springfield Township in suburban Cincinnati and Emmett Cooper of the Cincinnati suburb of Norwood, claim that by 1985, Givaudan and two predecessor companies, Tastemaker and Fries and Fries, knew that diacetyl harmed workers.