It seems microwave popcorn may cause a fatal rare lung disease. This news, which was announced earlier this week, was met with seemingly swift action by microwave popcorn makers. According to news reports, the four largest producers (Con Agra, General Mills, American Pop Corn Company, and Pop Weaver) have all acted and announced they will stop using the harmful ingredient diacetyl in their brands. Swift action before calls to remove the ingredient could get any louder. Take note.