The Blacklist: Worst Geek Bar Flavors (Ranked) EightVape Vaping releases toxic chemicals, including heavy metals, as well as ultrafine particles that go deep into the lungs. These increase the risk of heart and lung disorders. These could be the worst vape flavours for your health, according to science BBC Science Focus Magazine Vaping is on the rise. While e cigarettes don't contain tobacco, they may still contain many of the same toxic and cancer causing chemicals found in regular cigarettes. This includes: Acrolein (weed Vapes on black market may contain toxic chemicals, pesticides, harmful flavorings Shit Vape Flavor: The Ultimate Guide to Bizarre Vape Juice