the nicotine found in most vapes now days are the newer synthetic variety
after talking to the lab responsible we were told the main difference between synthetic and real is that the synthetic does not cause cancer
another difference is the real nicotine derived from the tobacco plant is usually sourced from India just like your kitchen spices like vanilla and is prone to contamination from ground pollution like heavy metals
synthetic nicotine solves several problems including reducing the strain on the planet by using less resources than required for growing large crops of tobacco
combine that with green chemistry which uses no heavy metals for a catalyst and you have a clean product
now onto flavorings
some such as isoamyl acetate for banana flavor are not very harmful to vape and is even used to test breathing equipment
extensive studies some on a global scale have been done to show the varying degrees of toxicity to nontoxicity on the various flavors
some flavorings are also good on the environment not only because of green chemistry but also with the newer technologies of reclaiming atoms and molecules from food waste
there is lab on the east coast of the US doing just that and making chemicals some for flavoring such as isoamyl acetate which has multiple applications
articles like this are deadest on turning back the clock on good science and good health