Opinion The Formaldehyde in Your E Cigs The New York Times E cigarettes almost always contain nicotine. Vaping can expose you and others around you to harmful chemicals, such as: E cigarette aerosols contain many dangerous metals and chemicals things that our lungs were never meant to inhale. One such chemical you might not be aware of is formaldehyde, which can be released as About E Cigarettes (Vapes) Smoking and Tobacco Use CDC Formaldehyde levels in e cigarettes were previously 'underestimated', researchers find The Pharmaceutical Journal