E cigarettes examined: Do they contain formaldehyde? Is vaping more dangerous than smoking? UK Addiction Treatment Centres Vapes don't produce harmless water vapor. They can contain addictive nicotine, cancer causing chemicals like acetaldehyde and formaldehyde, as well as heavy metals that don't belong in your body. Live Vape Free is What's in an E Cigarette? American Lung Association Emissions from Electronic Cigarettes: Key Parameters Affecting the Release of Harmful Chemicals Environmental Science & Technology Vape Residue May Harm Unborn Babies' Immune Systems Respiratory Therapy