5 Vaping Facts You Need to Know Johns Hopkins Medicine Secondhand e cigarette aerosols expose kids to less nicotine than cigarettes, study finds, but can still be risky CNN Vaping refers to the act of inhaling and exhaling aerosol, often called vapor, produced by an electronic cigarette or similar device. These devices heat a liquid that usually contains nicotine, flavorings, and Juul study shows secondhand vaping emissions are less toxic than cigarette smoke