As more people turn to electronic cigarettes in a bid to kick their smoking habit, Tonight explores the growing concerns surrounding the nicotine alternative.
An estimated 1.3 million people in the UK now use electronic cigarettes, which some researchers say are helping to save millions of lives but Tonight has found eight years after the products first appeared in the country, there appears to be no adequate regulation in Britain, Europe or beyond.
Glenn Thomas of the World Health Organisation told the programme: "We still need more research to know and understand what sort of impact on health and people these E-cigarettes are having.
"We know that a lot of the toxins which are consumed through E-cigarettes have not been adequately researched."
Watch The Rise of the E-Cigarette: Tonight at 7.30pm on Thursday on ITV
More top news
A woman who attempted to get her idol's full pout was left with hugely swollen lips when her plan went horribly wrong.
All would-be MPs should be forced to tell voters what paid jobs they have and whether they would keep them if elected, Lord Bew has said.
A Para who won the Victoria Cross gave up his military history studies just weeks into the course as he wanted to be a part of it instead.