Ah yesvaping studies saying they contain diacetyl. : r Vaping They may seem sweet and tasty, but each time you vape, you breathe in harmful chemicals. One of these chemicals is diacetyl, used in popcorn flavourings for its buttery taste. When eaten, Did you know some flavored vapes contain diacetyl, a chemical linked to popcorn lunga rare, irreversible lung disease? It scars the small airways, making it hard to breathe. Symptoms can mimic The FDA doesn't know if flavored vaping chemicals are safe to breathe Salon.com