Many dire warnings can be found on the web concerning a chemical used in microwave popcorn. The chemical is called diacetyl. Diacetyl is used to for artificial butter flavoring. It is the chemical in butter that gives it its characteristic taste. It is also a by-product of fermentation, and so it appears in wine and beer, producing slippery mouth-feel and “buttery notes.” It is used in a variety of foods to impart a butter-like flavor. The warnings about the chemical concern the possibility that inhaling the fumes from it can damage your lungs.
There have been animal studies conducted where acute inhalation to diacetyl damaged airways. And, in factories where the chemical is produced, it is possible that workers could be injured. In 1985, two employees in an Indiana food processing plant were diagnosed with bronchiolitis obliterans (BO), but the condition was not traced to diacetyl. Then in The 1999 and 2000, several cases of the condition were found in workers from a Missouri microwave popcorn plant, and diacetyl was ultimately determined to be the cause. The disease is extremely serious and causes shortness of breath, coughing, fatigue, and is ultimately fatal. Some of the workers involved were awaiting lung transplants at the time of the investigations.
After the danger of diacetyl exposure to factory workers was exposed, questions were raised as to the danger to consumers, and professional cooks.
One case of consumer exposure was reported in 2008 in an individual who ate at least 2 bags of microwave popcorn every day for 10 years. Diacetyl has received a great deal of media attention and industry concern, and lung injury resulting from its vapors has been dubbed popcorn lung. Note that the exposure to diacetyl that caused injury was extremely acute and long-term. The risk to people who do not work around diacetyl or who do not consume excessive amounts of the chemical is undoubtedly not as dire as most web sources contend. The chemical is still considered safe for use in foods, and it is a naturally occurring substance in dairy.
Is Microwave Popcorn Dangerous for Your Lungs?
Since 2007, almost all major manufacturers of microwave popcorn have stopped using diacetyl and now use other flavoring substitutes. Although diacetyl may still be used in some other products, it is not likely that you will come into contact with the vapors from the chemical often enough to damage your lungs. Current warnings of lung damage from microwave popcorn are largely unfounded.
What Other Foods Use Diacetyl?
Diacetyl is used in the following types of foods:
- chewing gum
- baked goods
- fats and oils
- imitation dairy products
- frozen dairy products
- milk products
- snack foods