E-cigarettes, also known as electronic cigarettes and vaporizer cigarettes are devices that emit doses of vaporized nicotine that are inhaled. The device is battery-operated and can also emit non-nicotine vaporized solutions. Manufacturers say they are an alternative for tobacco smokers who want to avoid inhaling smoke. Tobacco smoke contains over 4,000 different chemicals, many of which are hazardous for human health.
E-cigarettes are long-shaped tubes, many look like the product the user used to smoke, such as a cigarette, cigar or pipe. Some look like ballpoint pens (biros). The majority are reusable with replaceable and refillable cartridges. A small percentage of products are throw-away ones - disposable e-cigarettes.
Traditionally, the harm from smoking is caused primarily through the toxins produced by the burning of tobacco. By contrast, non-tobacco, non-smoked nicotine products, although addictive, are considerably less harmful. While electronic cigarette vapour can contain some of the toxins present in tobacco smoke these are at much lower levels.
Aside from the stench of tobacco cigarette smoke vs. the non-offensive or usually pleasant scents associated with vaping, burning tobacco generates a smoke that is a toxic cocktail of chemicals that affect not only the smoker, but others as well.
Vaping is no safer than smoking, scientists have warned after finding that e-cigarette vapour damages DNA in ways that could lead to cancer.
Scientists and health officials are divided over whether they are safe. Earlier this year Public Health England urged smokers to switch to vaping, saying e-cigarettes were far safer than traditional tobacco.
But the World Health Organisation and scientists from the London School of Hygiene and Tropical Medicine and the University of Liverpool remain concerned about their safety.
However, several 2013 publications show minimal evidence that e-cigarettes help smokers quit. A cross-sectional study of 1,836 tobacco smokers finds a significant association with e-cig use and "unsuccessful quitter" status but none with 'quitter" status.