Don't be foolede cigs or vapes may be less harmful than cigarettes, but less harmful doesn't mean safe. Vapes can contain harmful substances including nicotine, heavy metals like lead, volatile organic compounds and Nicotine found in 'nicotine free' e cigarette liquids sold in Australia, study finds ABC News Discover ePuffer Nicotine Free Vape Devices: Disposable E Cigarettes, E Cigars, and E Liquid Flavours in Canada Vaping is likely to cause oral and lung cancer, according to a comprehensive review of over 100 studies of the effects of nicotine based e cigarettes, published this week in the journal, Carcinogenesis.