More and more people are turning to e-cigs as an alternative to cigarette smoking and a pleasurable way to get their daily 'nicotine' fix. However, many people new to e-cigs are not aware of the dangers that nicotine can pose.

Nicotine is a toxic substance which, when taken in sufficient amounts, can be fatal. Nicotine in any form should not be used by children, people with high blood pressure, anyone with a heart condition or pregnant women. 

Just a small amount of nicotine is enough to kill a child or family pet. For this reason, e liquid that contains nicotine must never be left within their reach and should ideally be kept in a lockable box.

Nicotine tolerance varies greatly from person to person, but a lethal dose of nicotine for adults is estimated to be between 30 and 60mg.

For a child, a lethal dose is considered to be just 10mg of nicotine!

E liquid, the 'fuel' for e-cigs, is available in small bottles with nicotine concentrations of 0mg (nicotine free), 11mg, 18mg, 24mg and 36mg or 1.1%, 1.8%, 2.4% and 3.6% respectively. Nicotine concentration may vary slightly depending on the manufacturer, e.g., available in 16mg rather than 18mg bottles.

Cartridges are usually available with nicotine content labelled zero, low, medium and high.

Nicotine content in e liquid is usually measured in mg per ml. For example, 18mg e liquid would contain 18mg of nicotine per 1 ml of liquid. The exception to this is e liquid produced by manufacturer Johnson Creek which is measured in mg per 1.2ml.

One average tobacco cigarette contains approximately 11mg - 13mg of nicotine.