E-cigarettes have become a billion dollar industry, with one in five North Americans trying the product. But how safe are the battery operated devices?

E-cigarettes have a liquid cartridge filled with propylene glycol, a common chemical used in food products. It’s vapourized into a flavoured mist, mimicking cigarette smoke.

Vancouver businessman Babak Maghfourian is the founder of Wink E-cigarettes.

"The mango flavour is the favourite as of right now. We just came out with two flavours, watermelon and vitamin C," said Maghfourian.

The Wink cigarettes come with a lithium ion battery and charger you plug into your computer. 

"It's just water vapour and flavouring. There's no nicotine, no tar, no ash, no odour," said Maghfourian.

But are these E-cigarette's really safe?

Dr. Milan Khara runs the Smoking Cessation Clinic at Vancouver General Hospital and says it’s not proven that the device is risk-free and there is some evidence that propylene glycol mist can cause irritation to the airways.

"We can say with some degree of confidence that compared to smoke, cigarette smoke, compared with 6,000chemicals, this is almost certainly going to be preferable," said Dr. Khara.

Very little research has been done on e-cigarettes’safety, even though the devices are expected to outsell regular cigarettes within the decade.

Health Canada told CTV News in an email "as the safety, quality and efficacy of these products remains uncertain, Health Canada continues to advise Canadians not to use electronic cigarettes as they may pose health risks."

Still, a study published in The Lancet medical journal found e-cigarettes containing nicotine were as good or better than nicotine patches at helping smokers kick the habit. Almost 60 per cent of the smokers using e-cigarettes in the study were able to cut their daily tobacco cigarette consumption in half after six months.

E-cigarettes with nicotine cartridges are illegal for sale here in Canada, but easy to purchase online.

A single-use e-cigarette lasts about as long as a package of cigarettes and costs around $10. An e-cigarette kit that includes the cigarette and different cartridges, plus a battery charger sells for around $30.