Electronic cigarette

An **electronic cigarette**, also known as **e-cigarette** among other names, is a handheld battery-powered vaporizer that simulates smoking and provides some of the behavioral aspects of smoking, including the hand-to-mouth action of smoking, but without burning tobacco.[2] Using an e-cigarette is known as "vaping" and the user is referred to as a "vaper."[3] Instead of cigarette smoke, the user inhales an aerosol, commonly called vapor.[4] E-cigarettes typically have a heating element that atomizes a liquid solutioncalled e-liquid.[5] E-cigarettes are automatically activated by taking a puff;[6] others turn on manually by pressing a button.[3] Some e-cigarettes look like traditional cigarettes,[7] but they come in many variations.[3] Most versions are reusable, though some are disposable.[8] There are first-generation,[9] second-generation,[10] third-generation,[11] and fourth-generation devices.[12] There are also pod mod devices that use nicotine in the form of a protonated nicotine, rather than free-base nicotine found in earlier generations.[13] E-liquids usually contain propylene glycol, glycerin, nicotine, flavorings, additives, and differing amounts of contaminants.[14] E-liquids are also sold without propylene glycol,[15] nicotine,[16] or flavors.[17]

The benefits and the health risks of e-cigarettes are uncertain.[18][19][20] There is tentative evidence they may help people quit smoking,[21] although they have not been proven to be more effective than smoking cessation medicine.[22] There is concern with the possibility that non-smokers and children may start nicotine use with e-cigarettes at a rate higher than anticipated than if they were never created.[23] Following the possibility of nicotine addiction from e-cigarette use, there is concern children may start smoking cigarettes.[23] Youth who use e-cigarettes are more likely to go on to smoke cigarettes.[24][25] Their part in tobacco harm reduction is unclear,[26] while another review found they appear to have the potential to lower tobacco-related death and disease.[27] Regulated US Food and Drug Administration (US FDA) nicotine replacement products may be safer than e-cigarettes,[26] but e-cigarettes are generally seen as safer than combusted tobacco products.[notes 1][29][30] The risk of early death is anticipated to be similar to that of smokeless tobacco.[31] The long-term effects of e-cigarette use are unknown.[32][31][33] The risk from serious adverse events was reported in 2016 to be low.[34] Less serious adverse effects include abdominal pain, headache, blurry vision,[35] throat and mouth irritation, vomiting, nausea, and coughing.[36] Nicotine itself is associated with some health harms.[37] In 2019 and 2020, an outbreak of severe lung illness throughout the US was linked to vaping.[38]

E-cigarettes create vapor made of fine and ultrafine particles of particulate matter,[36] which have been found to contain propylene glycol, glycerin, nicotine, flavors, small amounts of toxicants,[36] carcinogens,[39] and heavy metals, as well as metal nanoparticles, and other substances.[36] Its exact composition varies across and within manufacturers, and depends on the contents of the liquid, the physical and electrical design of the device, and user behavior, among other factors.[notes 2][4] E-cigarette vapor potentially contains harmful chemicals not found in tobacco smoke.[40] E-cigarette vapor contains fewer toxic chemicals,[36] and lower concentrations of potential toxic chemicals than cigarette smoke.[41] The vapor is probably much less harmful to users and bystanders than cigarette smoke,[39] although concern exists that the exhaled vapor may be inhaled by non-users, particularly indoors.[42]

Since their entrance to the market in 2003,[9] global use has risen exponentially.[42] In a 2014 survey, about 13% of American high school students reported using them at least once in the previous month,[43] and in 2015 around 10% of American adults were users.[44] In the UK, users have increased from 700,000 in 2012 to 2.6 million in 2015.[45] About 60% of UK users are smokers and about 40% are ex-smokers, while use among never-smokers in the UK is negligible.[45] Most still use traditional cigarettes, raising concern that dual use may "delay or deter quitting".[36] Most peoples' reason for using e-cigarettes involve trying to quit smoking, though a large proportion use them recreationally.[6] It is commonly stated that the modern e-cigarette was invented in 2003 by Chinese pharmacist Hon Lik, but tobacco companies had been developing nicotine aerosol generation devices since as early as 1963.[46] As of 2018, 95% of e-cigarettes were made in China.[13] Because of overlap with tobacco laws and medical drug policies, e-cigarette legislation is being debated in many countries.[47] The revised EU Tobacco Products Directive came into effect in May 2016, providing stricter regulations for e-cigarettes.[48] As of August 2016, the US FDA extended its regulatory power to include e-cigarettes.[49] Large tobacco companies have greatly increased their marketing efforts.[26] As of 2014, there were 466 brands of e-cigarettes,[50] with global sales of around $7 billion.