E-cigarettes need to be more strictly controlled to stop teenagers using them, health professionals have argued.
The call was prompted by new research showing that 19% of 14-17 year olds have tried the products despite them only becoming available in recent years.
An analysis by researchers at Liverpool John Moores University found that the e-cigarettes were used by 5% of teenagers who had never smoked, 50% of former smokers and 67% of light smokers.
The survey asked over 16,000 teenagers in the North West of England about whether they used e-cigarettes.
Because they are relatively new, there is little evidence about the long-term health effects of e-cigarettes.
“Providing a concentrated form of a highly addictive substance, with known problems associated with it, and we need to be very cautious about that and how we protect our young people,” Professor Mark Bellis, one of the study’s authors, told BBC News.
There are currently no age restrictions on the purchase of electronic cigarettes but the Government has announced plans to ban under 18s from buying them.
Last summer the World Health Organisation called for the use of the products to be banned indoors.
Scientists from John Hopkins University in the US produced evidence last month that 'vaping' could increase the risk of contracting flu or pneumonia.
A US-wide study published last month found that 36% 13- and 14-year-olds who smoked e-cigarettes had never smoked a tobacco cigarette.
But some people argue that e-cigarettes have public health benefits because they could be less dangerous than tobacco smoking.
Despite being a relatively recent mass-market innovation, e-cigarettes are increasingly popular.
Sales of the products increased by 50% in the UK last year, according to the market research firm Nielsen.Reuse content