Both Pop Weaver and ConAgra this week announced that they will remove diacetyl from popcorn flavoring, following reports linking it with bronchiolitis obliterans syndrome (BOS), an incurable disease that causes thickening and scarring of the lungs. Reports of diacetyl's harmful effects are growing almost by the hour, and more and more BOS sufferers are surfacing, presenting companies with a possible legal nightmare that could cost them millions of dollars in compensation. Cathy Yingling, Pop Weaver's spokesperson, told FoodProductionDaily-USA.com that plant workers had not shown any symptoms of BOS, but that the company had removed the chemical from its butter flavoring as a preventative measure. "We made the decision to remove diacetyl from our products because we recognized that it was a growing concern," she said. From now on the company will use another formulation for popcorn flavoring, "that maintains the buttery flavor," Yingling explained, although she would not specify the exact formulation. ConAgra Foods similarly announced that it will reformulate the recipes for its Orville Redenbacher and Act II popcorn brands, over concerns for "worker safety". "We don't know how soon we will be able to replace diacetyl with a different butter flavoring, but the change will be made sometime over the next year," said spokesperson Stephanie Childs.More and more companies are now being spurred into action, especially after one report has linked popcorn and BOS outside of a factory environment. A US doctor reported Tuesday that a BOS case has now been found in a consumer who developed the disease after microwaving popcorn several times a day for years. Dr Cecile Rose, a pulmonary specialist at Denver's National Jewish Medical and Research Center, wrote to federal agencies warning that the case may prove that diacetyl is dangerous to health even when it is not used in industrial quantities. In response, the Flavor and Extract Manufacturers Association (FEMA) issued a statement yesterday recommending that its members reduce the amount of diacetyl used in product formulation. "This new information suggests a possible association between inhaling the fumes from the preparation of several bags of heavily butter-flavored microwave popcorn each day when the butter flavor contains diacetyl and the development of the patient's severe respiratory illness," the statement said. According to the Associated Press, the US Environmental Protection Agency will soon publish the first government study looking at what fumes are produced by microwaving popcorn at home. Industry fears were initially raised after researcher from the Netherlands linked the industrial use of Diacetyl, often used in flavorings for snacks, sweets and frozen foods, with the debilitating lung disease. The team, from the Universiteit Utrecht's department of environmental epidemiology examined a population of workers at an unnamed chemical plant that produced diacetyl, and found a cluster of previously undiagnosed BOS cases They then traced 196 former workers who were still living and who had been employed at the diacetyl production plant between 1960 and 2003, when the plant closed. They identified 175 who consented to complete exposure and respiratory health questionnaires and undergo lung function tests and clinical assessments. Of the 102 process workers considered to be at the highest risk for exposure, researchers positively identified three cases of BOS, and later, a fourth, in a worker who had initially declined to participate in the research. "This is the first study where cases of BOS were found in a chemical plant producing diacetyl," wrote Fritz van Rooy, who led the team While the researchers said they were unable to rule out contributions of other chemicals to the development of BOS, the study significantly narrows the field of suspects to diacetyl and the components and byproducts of its manufacturing process. Once inhaled, BOS leads to inflammation and obstruction of the lungs through rapid thickening or scarring of the small airways. The disease is irreversible, progressive and can cause death, with the only possible treatment available being a lung transplant. California is now considering a bill to forbid the use of diacetyl in the state's food industry by 2010, while Connecticut senator Rosa Delauro has asked the Food and Drug Administration to ban the chemical across the US until its effects can be properly examined. The chemical is approved for use in the EU. The European Food Safety Authority is currently evaluating diacetyl, a spokesperson said.