Questions and Answers about Diacetyl

What is diacetyl and where is it found?
Diacetyl and related compounds produce the buttery odor and flavor of many foods.  It occurs as a natural byproduct of fermentation and is found in several dairy products like butter, cheese and milk as well as in bread, coffee, brandy, and rum.  It also is manufactured as a component of artificial butter flavoring that is used in butter-flavored microwave popcorn, candy, baked goods and cake mixes. 

Are there other flavors like diacetyl?
Yes. The U.S. Food and Drug Administration (FDA) defines replacement flavors or flavoring agents as “substances added to impart or help impart a taste or aroma in food.” There are also flavor enhancers, which are “substances added to supplement, enhance, or modify the original taste and/or aroma of a food, without imparting a characteristic taste or aroma of its own.” Flavors and flavor enhances are considered part of the larger group of food additives which the FDA regulates.  This includes determining their safe use in food. For more information on food additives, please view the “Food Ingredients and Colors” brochure, developed by the IFIC Foundation in partnership with FDA.

Are there any significant health risks in consuming foods containing diacetyl?
No.  The FDA currently classifies diacetyl as “Generally Recognized as Safe” (GRAS) for consumption. 

What about potential health effects of inhaling diacetyl vapors?
Concerns about inhalation of diacetyl vapors stem from worker safety issues, not from the general public consuming or smelling foods flavored with diacetyl in the home. Interest in the possible inhalation effects of diacetyl first arose when workers in a microwave popcorn production facility developed breathing problems in the late 1990’s.  Since that time, experience with people working in factories around diacetyl and research in animals has suggested that frequent and repeated breathing of high concentrations of diacetyl in the air may be associated with an extremely rare lung condition known as bronchiolitis obliterans.  This condition can cause scarring of the small airways in the lung, which can result in less air exchange in the airways and over time, airway blockage. As with most medical issues, an individual’s medical history and ongoing medical conditions may influence their response to diacetyl, so some individuals may be more sensitive than others to the inhalation effects of diacetyl.

In April 2007, the Occupational and Safety Health Administration (OSHA) launched a program to address hazards and control measures associated with factories where butter-flavored microwave popcorn is produced. The FDA continues to seek additional information to help further clarify any health effects from diacetyl.

Is the industry doing anything about the potential health effects to workers?
Yes.  Because of the potential health risks from repeated exposure, the industry has implemented changes to reduce workplace exposure to diacetyl, including implementing engineering controls such as closed mixing tanks, separate mixing rooms for butter flavors, requiring respirators for mixing room operators, and improving air circulation in facilities. 

Putting the Risk in Perspective: Here’s What you Need to Know . . .
There is currently no evidence of health risks to the general public from preparing or consuming butter-flavored popcorn, or any other product containing diacetyl, in the home, as directed. These products can be enjoyed along with a healthful diet rich in nutrients. Current research indicates that there may be a potential health risk to individuals who are repeatedly exposed to high concentrations of diacetyl vapors for an extended period of time, such as individuals who work in facilities that manufacture or use certain flavorings containing diacetyl. However, these concerns do not apply to the average person consuming products containing diacetyl.