Bronchiolitis Obliterans also known as Popcorn Workers Lung, is an obstructive lung disease in which the bronchioles of the lungs are blocked by the growth of fibrous tissue.
The moniker Popcorn Workers Lung has been given to Bronchiolitis Obliterans because workers in factories that make microwavable popcorn that uses diacetyl for the buttery flavoring are known to contract the disease. The disease is irreversible, and can become so severe that a lung transplant may be necessary. Popcorn Workers Lung is a rare disorder that is known to be caused by repeated exposure to toxic gases, namely diacetyl.