Popcorn lung – otherwise known as bronchiolitis obliterans – is a severe, but uncommon, lung disease caused by a build-up of scar tissue which hinders the flow of air.
It got its name when workers in a popcorn factory developed the condition after breathing in the chemical diacetyl, which was used to give popcorn a buttery flavour.
Cancer Research UK says, ‘there have been no confirmed cases of popcorn lung reported in people who use e-cigarettes’ and that vapes do not cause the disease.
Diacetyl is banned as a vape flavouring in the UK and EU but is one of thousands of chemicals found in cigarette smoke.