What are e-cigarettes?

An e-cigarette is a long tube that usually resembles a cigarette, a cigar, a pipe, or a pen. Most are reusable, with replaceable and refillable cartridges, but some are disposable.

The first patent for a “smokeless, non-tobacco cigarette” was requested by Herbert A. Gilbert in 1963, but the current device did not appear until 2003.

The e-cigarette as we know it was invented by Hon Lik, a Chinese pharmacist, working for Golden Dragon Holdings, now known as Ruyan. The company started exporting into major markets in 2005 to 2006. There are now over 460 different brands on the market.

How they work

Most e-cigarettes have:

  • a mouthpiece, or cartridge
  • a heating element
  • a rechargeable battery
  • electronic circuits

As the user sucks on the mouthpiece, a sensor activates a heating element that vaporizes a flavored, liquid solution held in the mouthpiece. The person then “vapes,” or inhales, the aerosol solution.

The nicotine content varies from zero to “extra-high,” or 24 to 36 milligrams (mg) per milliliter (ml).

The mouthpiece is a cartridge that is fixed to the end of a tube. A small plastic cup within the mouthpiece holds an absorbent material drenched in the liquid solution.The cartridge can either be refilled or replaced with another pre-filled cartridge when necessary.

The atomizer is a heating element that heats the liquid, causing it to vaporize. The solution can then be breathed in, or inhaled.

The battery powers the heating element. This is normally a rechargeable, lithium-ion battery.

The sensor activates the heater when the user sucks on the device. An LED may show when it is activated.

The solution, also known as e-liquid or e-juice, is made by extracting nicotine from tobacco and mixing it with a base, usually propylene glycol, and flavoring. Propylene glycol is used in inhalers, for example, for asthma. There is a wide range of flavors to choose from, with names such as traditional, watermelon, menthol, and lava flow.

Some flavors, such as a combination of tobacco and menthol, try to resemble traditional cigarettes. A number of them claim to mimic specific brands.