by Christian Nordqvist

15 Feb 2011

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.

Manufacturers and a significant number of users say the e-cigarette provides a similar sensation to inhaling tobacco smoke, however, there is no combustion (no smoke).

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.

The electronic cigarette first entered the market in China in 2004. In 2003, Hon Lik, a pharmacist from China invented the device. Golden Dragon Holdings, the company Lik worked for, started exporting into major markets in 2005-2006. Golden Dragon Holdings changed its name to Ruyan.

Most of the current models are automatic - as the user sucks on it, a sensor activates a heating element that vaporizes a liquid solution held in the mouthpiece. The user can choose whether or not to have nicotine in the flavored liquid solution. In older models (manual models), there is a little button which turns the heating element on and off. An LED indicates whether the device has been activated when the user inhales.

The E-cigarette has various components

Most devices have a mouthpiece, a heating element, a battery (rechargeable), and some electronic circuits.

• The mouthpiece - also known as the cartridge. This is fixed to the end of the tube. A smaller plastic cup within the mouthpiece holds an absorbent material drenched in liquid solution. The solution can carry varying levels of nicotine. Manufacturers refer to the mouthpiece as the cartridge. This can either be refilled or replaced with another pre-filled one when necessary. Instead of using the cartridge, the user can also use drip tips - the absorbing material is removed and drops of liquid are placed directly into the atomizer bridge.
• The Atomizer - this is a heating element which heats up the liquid, causing it to vaporize so that it can then be breathed in (inhaled). An atomizer needs to be replaced periodically, usually about once every 3 to 6 months.
• The battery and some electronic components - in most cases there is a lithium-ion battery which is rechargeable. The battery powers the heating element. The battery life depends on how often you use it, its type, size and operating environment. It is usually the largest component of an electronic cigarette. Newer versions have a sensor which automatically activates the heating method as soon as somebody sucks on the device, while others have a button you need to press when you suck. Many have an LED (light emitting diode) which tells when the device is activated.

What do the cartridges contain?

The solutions are often referred to as e-liquid or e-juice. Typically, they contain hundreds of flavors. For those desiring nicotine without smoke, the solution contains nicotine dissolved in propylene glycol and/or vegetable glycerin - both common food additives. Experts say propylene glycol has had no serious known side effects since the 1950s when it was included in nebulizers and asthma inhalers. In fact, the FDA (Food and Drug Administration), USA, includes this ingredient as one of its GRAS (Generally Recognized as Safe) substances.

The solutions come in varying levels of nicotine concentrations, ranging from zero to extra-high (24-36 mg/ml).

Some flavors, such as tobacco/menthol combinations, try to resemble traditional cigarettes. A number of them claim to mimic specific brands too.

From Medical News Today.