Diacetyl, the ingredient that imparts odour and flavour of the butter in popcorn has once again been linked to increasing risk of lung disease, this time in an animal study.
"Workers making microwave popcorn and flavouring chemicals are at increased risk for developing lung disease," said lead researcher, Ann Hubbs of the Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, (NIOSH), Centers for Disease Control and Prevention in Morgantown.
"This research, in conjunction with other recent studies, supports the conclusion that diacetyl is an inhalation hazard and further studies are needed to also investigate other agents in butter flavouring so we have the information needed to protect workers."
Diacetyl is easily vaporized at temperatures used in microwave popcorn production, which results in high concentrations in the workplace.
The occupational disease bronchiolitis obliterans syndrome (BOS), or "popcorn worker's lung" was first acknowledged in 2001 among the workers of an American chemical plant that produced microwave able popcorn.
The study is published in the current issue of Toxicologic Pathology.