Second hand vape smoke linked to more asthma symptoms in kids Vaping Around Babies How Secondhand Vapor Smoke Can Harm Kids Truth Initiative Secondhand smoke is classified as a Group A carcinogen, a substance known to cause #cancer in humans and animals. Learn more at the link in Instagram Sitting somewhere when a cloud of cotton candy vapor washes over you? If you can smell the sweet scent of a vape, that's not a great sign.