TarStar

Chemicals · 95/99

DiacetylC₄H₆O₂

The compound that gives popcorn its butter taste.

Diacetyl is used to create butter flavour in margarine and microwave popcorn. The problem is not eating it but INHALING it: in 2000, workers at a microwave popcorn plant were found to have an irreversible lung disease (bronchiolitis obliterans, known as "popcorn lung"), and a NIOSH investigation identified the flavouring as the cause. In 2026 the FDA added diacetyl to its list of harmful constituents in tobacco products; it is present in, or generated by, most e-liquids. The disease has not yet been described in people who vape — the concern comes from the evidence in workers.

Source: FDA HPHC · CDC/NIOSH

The substances come from three sources: the U.S. Food and Drug Administration's list of harmful and potentially harmful constituents in tobacco products, and reports from the World Health Organization and the U.S. Surgeon General. Carcinogen classifications come from the International Agency for Research on Cancer (IARC). Each card names its own source underneath.

FDA HPHCIARCSurgeon General raporuDSÖCDCCDC/NIOSHTobacco Control (2008)

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