(NaturalNews) You might be reassured to learn that the buttery flavor in microwave popcorn typically comes from a chemical actually found in butter, but you shouldn’t be. This chemical, called diacetyl, is so toxic that it commonly destroys the lungs of workers in microwave popcorn factories, afflicting them with the crippling and irreversible disease known as bronchiolitis obliterans. Bronchiolitis obliterans is so rare outside of this context that it has become more commonly known as “popcorn lung,” after the primary cause of the disease.