Levels of selected carcinogens and toxicants in vapour from electronic cigarettes

Tob Control. 2014 Mar;23(2):133-9. doi: 10.1136/tobaccocontrol-2012-050859. Epub 2013 Mar 6.


Significance: Electronic cigarettes, also known as e-cigarettes, are devices designed to imitate regular cigarettes and deliver nicotine via inhalation without combusting tobacco. They are purported to deliver nicotine without other toxicants and to be a safer alternative to regular cigarettes. However, little toxicity testing has been performed to evaluate the chemical nature of vapour generated from e-cigarettes. The aim of this study was to screen e-cigarette vapours for content of four groups of potentially toxic and carcinogenic compounds: carbonyls, volatile organic compounds, nitrosamines and heavy metals.

Materials and methods: Vapours were generated from 12 brands of e-cigarettes and the reference product, the medicinal nicotine inhaler, in controlled conditions using a modified smoking machine. The selected toxic compounds were extracted from vapours into a solid or liquid phase and analysed with chromatographic and spectroscopy methods.

Results: We found that the e-cigarette vapours contained some toxic substances. The levels of the toxicants were 9-450 times lower than in cigarette smoke and were, in many cases, comparable with trace amounts found in the reference product.

Conclusions: Our findings are consistent with the idea that substituting tobacco cigarettes with e-cigarettes may substantially reduce exposure to selected tobacco-specific toxicants. E-cigarettes as a harm reduction strategy among smokers unwilling to quit, warrants further study. (To view this abstract in Polish and German, please see the supplementary files online.).

Keywords: Carcinogens; Electronic nicotine delivery devices; Harm Reduction; Toxicology.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Inhalation
  • Carcinogens / analysis*
  • Drug Delivery Systems*
  • Electronics*
  • Harm Reduction
  • Humans
  • Metals, Heavy / analysis
  • Nicotine / administration & dosage*
  • Nitrosamines / analysis
  • Noxae / analysis*
  • Smoking*
  • Tobacco / chemistry
  • Tobacco Products
  • Toxicology
  • Volatile Organic Compounds / analysis


  • Carcinogens
  • Metals, Heavy
  • Nitrosamines
  • Noxae
  • Volatile Organic Compounds
  • Nicotine