““commercial popcorn is likely to contain additives linked to asthma. At one cinema, an attendant explained how they add a premix powder. ‘I wouldn’t eat it,’ she said. ‘There’s a lot of powder, I don’t know what’s in it.’ From reading supermarket labels, I guess it could contain yellow colours – either artificial or annatto – and possible synthetic antioxidants in the vegetable oil, as well as diacetyl butter flavour.””