Cancer Risk Boosted by Formaldehyde in E Cigarettes Formaldehyde exposure from 3 e cigarette formats tested well below WHO quality guidelines EurekAlert! What's really inside a vape? Many people think vaping is just flavored vapor, but the aerosol from e cigarettes can contain harmful substances that go straight into the lungs. According to the Carbonyl Compounds Generated from Electronic Cigarettes E cigarettes can emit formaldehyde at high levels under conditions that have been reported to be non averse to users Scientific Reports