Ronald Kuiper, who was being treated at St. Luke’s Regional Medical Center in Sioux City and had less than 30 percent breathing capacity, was felled by flavoring commonly found on microwave popcorn. Kuiper died of the so-called ’popcorn lung disease.’

The key to Kuiper’s demise is a chemical known as diacetyl. While it is generally felt that the chemical poses little threat to consumers, the fumes from diacetyl used in flavoring manufacturing are said to be harmful to factory workers exposed to large quantities in the workplace.