According to the National Cancer Institute, consuming food that has been cooked beyond a temperature of 248 degrees fahrenheit, which includes burned popcorn, may carry a health risk due to the formation of possibly carcinogenic acrylamide. Inhaling the smoke from burned popcorn could also pose a health risk.
While studies on humans are incomplete as of 2014, the World Health Organization has listed acrylamide in food as a major concern and emphasizes the need for more research on dietary acrylamide risks. The EPA classifies smoke as fine particles, which carry a higher likelihood of aggravating asthma or causing other respiratory symptoms.
