Cardiac surgeon Dr. Gopal Bhatnagar leads a double life, one that a lot of his medical colleagues might question. In between bypass surgeries, he tends to his side business as one of Canada's growing legion of e-cigarette entrepreneurs.

Eleven shops from B.C. to Nova Scotia carry his 180º smoke brand of e-cigarettes and accessories.

"You have an available worldwide market of $780 billion from smokers that are buying things they're addicted to, that is known to cause harm to them. And you have an alternative product that from my perspective is safer," he said, standing in his shop on Toronto's Yonge Street, still wearing his hospital green scrubs.

Despite Bhatnagar's perspective that e-cigarettes are safer, others contend that not enough research has been done on the long-term effects of the practice, known as vaping. Users are called vapers, since the devices emit water vapour, not smoke.

But some regulators aren't waiting for more evidence before taking action against the growing trend. Nova Scotia, Ontario and British Columbia are set to fold e-cigarettes into existing tobacco laws, which prohibit advertising, and regulate the age of buyers along with where users can indulge. The approach is opposite to what a House of Commons health committee recommended last month: that tobacco rules should not apply to e-cigarettes. Instead, all-new legislation should be drafted.

"Public health, government and vapers are at odds and yet we're all really interested in the same thing: reducing the harm of tobacco in society," said Bhatnagar, lamenting the provinces' stance.

What's in that stuff?

The problem with the new legislation, according to the Electronic Cigarette Trade Association (ECTA), is that the provinces are focusing on where e-cigarettes can be used, instead of what's in them.

"So many of the rules relate to where vaping is allowed, and that's something that should be further down the road, we're not even there yet," said Kate Ackerman of ECTA. "The first issue that needs to be addressed is manufacturing standards and labelling."

As an example, she points to the liquid inside e-cigarettes that fuels the vapour. Users need to re-fill their e-cigarettes regularly, by purchasing small vials of the liquid. Health Canada testified at the House of Commons committee that there have been cases where nicotine was found in liquids labelled as being free of the addictive substance. As well, with consumers buying the liquid online from China and other countries, lax labelling standards mean the products could contain any number of unlisted, potentially harmful ingredients.

It''s influential on youth and children. They're going to think that smoking is normal again, that it's OK to light up in a public space - Monica Sarkar, Ontario Lung Association

Even so, the popularity of the electronic devices is growing so quickly that the size of the industry can't be measured with accuracy. Estimates of what it's worth worldwide range from $1 billion to $3 billion annually. Ackerman won't even hazard a guess to how many so-called "vape shops" have opened in Canada, and says the number of websites selling the devices is "uncountable".

At a fraction of the cost, and without the smell and established health risks of real cigarettes, many smokers are jumping on the trend, using e-cigarettes as a quitting aid.

A visit to a vape shop in downtown Toronto is a hazy experience, with customers lined up at a "tasting bar", sampling various flavours, such as cinnamon, mango and tobacco.

Treat e-cigs like tobacco, health advocates say

Dr. Gopal Bhatnagar sells e-cigarettes and related products through 180smoke. (CBC) Monica Sarkar of the Ontario Lung Association is concerned about the trend. Along with the Canadian Cancer Society, her organization supports the provinces' strategies and wants to see further restrictions

"We want the public to know there are potential negative health outcomes from e-cigarettes, and they're not necessarily an effective quit smoking aid," Sarkar said.

She and others believe that whether e-cigarettes are harmful, the devices "re-normalize" smoking. With some vapers puffing away indoors at bars, theatres and on transit, critics say it could reverse the work done by governments and health agencies to make the habit socially unacceptable.

"It''s influential on youth and children," she said. "They're going to think that smoking is normal again, that it's OK to light up in a public space. And it can also act as a trigger for current smokers and those who are trying to quit — and even former smokers. So it really harms the kind of tobacco control efforts and accomplishments from the last 10 to 15 years."

As vaping increases, do smoking rates decline?

Dr. Bhatnagar calls the idea of re-normalization "a boardroom hypothesis."

"Someone on a committee somewhere, the FDA or the Centre for Disease Control, decided this could happen. But the data doesn't support this idea. Wherever vaping increases, the smoking rates fall."

His biggest worry is that new restrictions regarding where people can vape will backfire, and remove some of the impetus for people to quit combustible cigarettes for their electronic counterparts.

"I would like to see the industry regulated from a manufacturing standard perspective," he said. "You should not be brewing this stuff up in your garage and selling it out of big vats, or from your van."

The industry says it's important to get the legislation right, given that some forecasts predict e-cigarette sales will surpass those of regular cigarettes as early as 2020.

Nova Scotia's new e-cigarette restrictions take effect May 31, while Ontario's legislation comes into effect in January 2016. The B.C. government intends to announce its new proposed legislation in the coming months.