E-cigarettes are battery operated devices that aim to simulate combustible cigarettes. They don’t contain tobacco but operate by heating nicotine and other chemicals into a vapour that is inhaled. Nicotine is the addictive substance in tobacco but it is the many other chemicals in cigarettes that are responsible for smoking-related diseases. Electronic cigarettes deliver nicotine without the vast majority of these other chemicals, and it is for this reason that organisations such as the Medicines and Healthcare Products Regulatory Agency ( MHRA ) and the National Institute for Health and Care Excellence ( NICE ) have indicated that electronic cigarettes are less harmful than tobacco.