Vegetable glycerin,propylene glycol,flavors,nicotine. There is also a "state of california" warning about possible exposure to formaldehyde. Can't they test th

Vegetable glycerin,propylene glycol,flavors,nicotine. There is also a "state of california" warning about possible exposure to formaldehyde. Can't they test this on rats and monkeys easily to see if there is an obvious side effect? Or maybe they have and the results are inconclusive?