Secondhand Electronic Cigarette Aerosol and Indoor Air Quality US EPA Is Second Hand Vape Smoke Harmful Secondhand smoke and secondhand aerosol Secondhand Vape Exposure: Effects, Who's at Risk, and More 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