Wayne Watson, from Centennial, Colorado, is thought to be the only consumer of popcorn to have developed the rare lung condition bronchiolitis obliterans (popcorn lung).
Watson's lungs have been damaged by the flavour chemical diacetyl in the artificial butter flavour, something that previously only damaged popcorn factory workers who mixed large vats of popcorn.
Instead of taking on popcorn makers like the workers have done, Watson is suing the store that sold him his daily fix.
The lawsuit, which seeks unspecified damages, states that the companies "failed to warn that preparing microwave popcorn in a microwave oven as intended and smelling the buttery aroma could expose the consumer to an inhalation hazard and a risk of lung injury".
An investigation by the hospital who diagnosed Watson found factory workers were exposed to diacetyl levels between 0.75 and 4 parts per million. Tests in Watson's kitchen where the microwave would vent and where he would open popcorn bags showed levels between 0.5 and 3 parts per million, according to the hospital.
