the popcorn lung shit is such old news that people who bring it up have no idea what they are talking about. it was related to a chemical called Diacetyl. The popcorn lung name was from a industrial incident where workers were making popcorn with diacetyl as the flavoring, and there was an accident and they inhaled diacetyl vapors. There was no study done to say the levels in e-liquid cause this “popcorn lung” but e-liquid companies were so scared it would ruin their business that most removed the flavoring from their recipes, and the ones that contained it, had a warning that it had diacetyl, all without the goverment stepping in. vaping gets so much flak from the shit big-tobacco has done in the past decade and its sad where it is now, where people buy disposables and its just a dead market then what it used to be. just to put things into context here in canada. a 60ml bottle of eliquid used to cost 20-30 CAD before the “sin tax”. now, it costs 55-60 CAD for the same bottle. want to bypass the tax and DIY? sorry, nicotine bases to mix only go up to 20mg/ml FOR THE WHOLE BOTTLE meaning that if you want to make your juice, the whole bottle of nicotine base you bought is used for ONE BOTTLE MIX and is subjet to the sin tax. before you could buy a 100mg/ml bottle of nicotine for 40 bucks and it would last your months while you had your flavorings, and PG/VG bases.