Special electronic cigarettes designed to help smokers quit could be potentially lethal to children, according to a report.
Trading standards officers are calling for a ban on the sale of "e-cigarettes" to youngsters because of the high levels of nicotine contained in their refill cartridges.
The devices are battery powered and work by producing a fine mist that can be inhaled instead of smoke.
But some of the substitutes, which look like real cigarettes, contain up to 18 mg of liquid nicotine and could prove fatal if ingested, according to the Sun newspaper.
The government is being urged to put a health warning on all packs of e-cigarettes while making their sale illegal to under-18s.
Antismoking campaigners from Action on Smoking and Health (Ash) said though any alternatives to smoking were welcomed, there was no proof that this remedy designed in China was safe.
A spokesman told BBC Radio 5Live: "We're not entirely sure these products are safe and that is the problem. We haven't had the tests through yet that show they are safe and that is why the regulators are worried."
"Although stopping smoking will have benefits to health and help reduce unintentional injury from smoking implements HSS would have reservations over any toxic product being introduced to the home, particulary where young children or those with impaired awareness may be present." - Teresa Murphy, Chair, Home Safety Scotland
"The health benefits of stopping smoking are obvious but as a professional who is interested in unintentional injury within the home - particularly for children under 5 years old - I have very grave concerns regarding the high risk of young children gaining access to this product." - Margaret Brunton, Scotland
"I just got mine yesterday, my husband a few weeks ago. I honestly think I can quit smoking if I continue to use these! A little concerned how much nicotine I might be getting, but it beats the 3,999 other things I get from cigarettes. I'm now a vapor sign me up ;) But, please, if you have pets and kids keep them far away from this stuff!! Common sense alone should be enough, but I don't believe it will! Use extreme caution. And then enjoy your vaping, just be safe." - Carolyn, USA