The Welsh government said on Tuesday it would bring in a law to stop the use of electronic cigarettes in workplaces and indoor public spaces, becoming the first part of the United kingdom to bring in such a ban amid concern about their use and safety.
Mark Drakeford, the Health Minister for Wales, there was a danger that e-cigarettes provided normalized smoking and would be a "gateway" product which would encourage young people to take up regular cigarettes.
"We certainly don't want to make smoking seem acceptable. It kills one in two of the people who are unfortunate enough to be taking up the habit," Drakeford told BBC radio.
"We don't want to look back in five or 10 years time and say how much we wish we had acted."
Wales outlawed smoking in enclosed public places in 2008, a year after a similar ban in England, but no date has yet been given for when the e-cigarette restriction would come in.
While many experts believe e-cigarettes, metal tubes which heat nicotine-laced liquid into an inhalable vapor, are a lower-risk alternative to smoking, other health officials say their impact needs greater study.
Drakeford said 40 other countries around the world had already brought the use of e-cigarettes into line with limits on the use of conventional ones, a move he said the World Health Organization and British health officials had suggested was the best approach.
However, George Butterworth, tobacco policy manager at Cancer Research UK, said there was no evidence to justify a ban
by arguing e-cigarettes normalized smoking or produced a vapor which was dangerous to others.
"There are potential unintended consequences particularly that e-cigarettes are an opportunity for people to move away from tobacco smoking which is very, very bad for their health and we wouldn't want to put up any unnecessary barriers to prevent people from quitting cigarettes," he told BBC radio.
Drakeford said the Welsh ban was a balance and would do nothing to stop smokers using e-cigarettes to quit their habit.
The charity Action on Smoking and Health says more than 2 million adults in Britain use e-cigarettes and a survey in March said one in five teenagers had experimented with them..
Two studies published in April found e-cigarettes could help some smokers quit, but that it depended on the type and how often they were used.