E cigarettes almost always contain nicotine. Vaping can expose you and others around you to harmful chemicals, such as: E Cigarettes Vaping with Juul & Other Electronic Cigarettes Frontiers Carbonyl Emissions in E cigarette Aerosol: A Systematic Review and Methodological Considerations E Cigarettes and Cardiovascular Disease Risk: Evaluation of Evidence, Policy Implications, and Recommendations Current Cardiovascular Risk Reports Springer Nature Link Electronic cigarette aerosol contains 6 times less formaldehyde than tobacco cigarette smoke Nicorex