Diacetyl

Diacetyl, or 2,3-butanedione, is a volatile diketone with a characteristic buttery aroma. It is used as a flavoring agent in foods and beverages and occurs naturally in dairy products such as butter and cheese, as well as in beer and other fermented products. It can be produced synthetically or by microbial fermentation for industrial use.

In the food industry, diacetyl is added to impart a creamy, buttery note. It is commonly found in microwave popcorn flavorings, margarine, dairy desserts, confectionery, and baked goods, where it may appear as part of blends or direct formulations.

Safety and health: Inhalation exposure to diacetyl in occupational settings has been linked to bronchiolitis obliterans, a serious lung condition. Consumer exposure from foods is typically much lower, but workers handling diacetyl-containing flavorings require appropriate ventilation, containment, and protective measures.

Regulation and substitutes: Regulatory guidance often covers workplace exposure limits and control measures in flavor manufacturing. To reduce risk, some manufacturers have shifted to substitutes or reduced diacetyl use; alternatives such as acetoin and 2,3-pentanedione are used, although these compounds may entail their own hazards and require evaluation.