Unlike cigarettes, smoke free alternatives such as e cigarettes and heated tobacco products don't burn tobacco and that makes a big difference. Burning tobacco creates high levels of harmful chemicals. Heated tobacco products, UofL study shows nicotine in e cigarettes may not be harmless, as some claim The Russell County Newspapers Emissions from Electronic Cigarettes: Assessing Vapers' Intake of Toxic Compounds, Secondhand Exposures, and the Associated Health Impacts Environmental Science & Technology Are heated tobacco products a new health risk? Solvent Chemistry in the Electronic Cigarette Reaction Vessel Scientific Reports 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