Researchers at the National Institute of Occupational Safety and Health recently reported on the dangers of diacetyl and the substitute 2,3-pentanedione. Workers in various processing facilities nationwide, including here in Colorado, are at risk of developing an irreversible lung disease called bronchiolitis obliterans that may require life-long medical treatment. This occupational illness is also called popcorn lung. The chemicals apparently cause scarring and constriction of a worker's airways, and the symptoms include coughing, wheezing and breathing difficulties that may develop into more severe problems.
At-risk workers include those working at microwave popcorn processing plants, where diacetyl or its substitute is used to flavor the popcorn. This chemical is apparently also present in E-cigarettes, and research has indicated that workers who are present where coffee beans are ground, flavored, packed and stored are also at risk of contracting the lung disease. NIOSH says five coffee processing workers are known to suffer the condition, and researchers have subsequently determined that elevated levels of these dangerous chemicals are present in the air in coffee processing plants.