Comparison of the chemical composition of aerosols from heated tobacco products, electronic cigarettes and tobacco cigarettes and their toxic impacts on the human bronchial epithelial BEAS 2B cells ScienceDirect Estimated mass of flavoring chemicals in e cigarettes (g e cigarette) Download Table Vaping is often marketed as a safer alternative to smoking, but many vape products contain nicotine, harmful chemicals, and heavy metals that can harm developing brains and lungs. Vaping: How E cigs Work (Infographic) Live Science