Wales could be the first part of the UK to ban smoking e-cigarettes in enclosed public spaces.
Welsh health minister Professor Mark Drakeford said officials were considering a ban amid concerns the products could "re-normalise" the use of conventional cigarettes.
He said there were also concerns that their spread could undermine the ban on tobacco smoking in enclosed public spaces, making it more difficult to enforce.
"We have spent 30 years ... creating a climate in this country where people understand that smoking is not something that is to be regarded as glamorous or desirable. We are concerned that e-cigarettes might reverse that tide," he told the BBC Radio 4 Today programme.
"We are concerned that they might act as a gateway to conventional cigarettes. It contains nicotine, it's highly addictive and you might then find it easier to move on to conventional cigarettes."
Deborah Arnott, chief executive of health charity Ash, said: "The concern that electronic cigarettes may be a gateway into smoking is understandable.
"However, this is not borne out by the evidence so far from England, where our research shows that their use is almost without exception only amongst current and ex-smokers.
"There is growing evidence that they are effective in helping smokers quit and this is to be welcomed. We're pleased that the Welsh government is consulting on whether to ban their use in enclosed public places as it is important to take account of the evidence before going ahead."