Safety of electronic cigarettes

The safety of electronic cigarettes is uncertain. There is little data about their safety, and considerable variability among e-cigarettes and in their liquid ingredients and thus the contents of the aerosol delivered to the user. Reviews on the safety of e-cigarettes have reached significantly different conclusions. A 2014 World Health Organization (WHO) report cautioned about potential risks of using e-cigarettes. Regulated US Food and Drug Administration (FDA) products such as nicotine inhalers are likely safer than e-cigarettes,. A systematic review suggests that e-cigarettes are less harmful than smoking and since they contain no tobacco and do not involve combustion, users may avoid several harmful constituents usually found in tobacco smoke. However, e-cigarettes cannot be considered harmless.

E-cigarettes have been found to reduce lung and myocardial function, increase inflammation, and have toxic content including carcinogens, but to a much lower extent than combustible cigarettes in virtually all cases. The long-term effects of e-cigarette use are unknown. A 2015 study found serious adverse events related to e-cigarettes were hypotension, seizure, chest pain, rapid heartbeat, disorientation, and congestive heart failure but it was unclear to the degree they were the result of e-cigarettes. Less serious adverse effects may include abdominal pain, headache, blurry vision, throat and mouth irritation, vomiting, nausea, and coughing. A 2014 WHO report said, "ENDS [electronic nicotine delivery system] use poses serious threats to adolescents and fetuses." Aside from toxicity exposure in normal use, there are also risks from misuse or accidents such as nicotine poisoning (especially among infants and children), contact with liquid nicotine, fires caused by vaporizer malfunction, and explosions resulting from extended charging, unsuitable chargers, or design flaws. Battery explosions are caused by an increase in internal battery temperature and some have resulted in severe skin burns. There is a small risk of battery explosion in devices modified to increase battery power.

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