Diacetyl (also called butanedione or 2,3-butanedione) is a natural byproduct of
fermentation and is also synthesized by chemical manufacturers. Diacetyl gives
butter and certain food flavorings a distinctive buttery flavor and aroma.
Food flavorings containing diacetyl are used in microwave popcorn and other
snack foods, pet foods, candies, baked goods, and other food products.

The American College of Occupational and Environmental Medicine (ACOEM)
provides comments to the Rulemaking concerning Occupational Exposure to
Diacetyl and Food Flavorings Containing Diacetyl.

ACOEM represents more than 5,000 physicians and other health care professionals
specializing in the field of occupational and environmental medicine. ACOEM is
the pre-eminent organization of physicians who champion the health and safety
of workers, workplaces, and environments.

More info

AplusA-online.de - Source: American College of Occupational and Environmental Medicine