I'd wager that Chinese factories producing e-liquid on a large scale have cleaner environments than small vendors in the US.
Just saying.
I have personally toured many factories in china as a consultant to an electronics manufacturer in the US, and every one of them, at least on the production floor, was clean, efficient and well organized. And this is only for basic electronic accessories mainly cables, I imagine their juice production facilities are even more so, in fact they may be fairly automated. No one there cares about anything except the task at hand, producing high volume, they don't have the time or will for that matter to mischievously manipulate or sabotage the ingredients. Now there are always exceptions, and also this doesn't mean mistakes can't be made, but that's the case in all facilities isn't it? That being said, why would anyone buy anything but US made juice if there's no significant advantage to buying it from china? I mean do they have really really tasty juice or something? Does it recharge your batteries while you vape? If it's all relatively the same stuff, no matter from US or china, and close to the same pricing, then why not support your own economy? Who cares if the raw materials come from china, the people putting it together and selling/marketing and realizing profits are american. Come on...we all need to start buying american whenever possible...
Btw - If you tour one yourself watch the low ceiling room-room transitions, smacked my head so hard I barely avoided stitches. 6'-2" and a giant over there.