Even as some public-health advocates call for legalization, Health Canada has been vigorously applying its controversial ban on nicotine-loaded e-cigarettes, ordering scores of businesses to stop selling the devices and telling Internet providers and credit card companies to cut off the companies.
The regulator has investigated 250 complaints about sales of electronic cigarettes in the past four years and issued cease-and-desist letters to most of the businesses involved, said Leslie Meerburg, a spokeswoman.
The enforcement attempts come amid a spirited debate among public-health experts about whether e-cigarettes risk encouraging real smoking - or represent an effective stand-in for tobacco, minus the life-threatening side effects.
E-cigarette businesses and some anti-smoking advocates argue the government should be moving toward legalizing and regulating the devices, rather than "bullying" the retailers.
"We have never seen any product, nicotine-replacement therapy product, that has generated so much interest on behalf of the smokers. ... This is so amazing," said François Damphousse, a researcher with the Non-smokers Rights Association, one of Canada's most influential tobacco-control organizations.
"What you should do is permit it on the market and inform the public - 'If you have to make a choice because you're addicted, go for the safer product.' "
The battery-powered devices heat up a liquid that contains nicotine and flavouring, turning it into vapour and creating an experience akin to smoking, while providing a hit of the addictive drug. Missing are the thousands of chemicals, many of them carcinogenic, churned out by burning tobacco.
Citing the potential for "nicotine poisoning and addiction," and potential irritation from the propylene glycol liquid, Health Canada issued a notice in 2009 that barred sales of the devices if they contain nicotine.
Health Canada is sometimes criticized for a less-than-aggressive approach to enforcing its rules. The regulator has gone after e-cigarette sellers, however, with relative gusto, seizing or turning back product being imported into Canada, as well as demanding a sales halt in most of the 250 complaints it has investigated, said Ms. Meerburg.
No charges have been laid.
'If you have to make a choice because you're addicted, go for the safer product'
The department has also asked that Internet-service providers cease hosting websites selling e-cigarettes, and told credit card companies, or third parties like PayPal, not to handle the retailers' transactions, said Daniel David, head of the Electronic Cigarette Trade Association.
"It does slow down this industry, certainly," said Mr. David. "A lot of times it's a scare tactic. If you're a new company and Health Canada sends you a cease-and-desist letter, it can be pretty stressful."
The Northern Vapers store in Saanich, B.C., is one of those to receive a stop-sale letter. "They're just trying to intimidate people," charged owner John Overall.
Mr. David is convinced the devices work like no other smoking-cessation tool, rapidly weaning him off tobacco, and doing the same for "70-80%" of customers at his Evape stores.
However, many public-health experts are disturbed by the growing interest in "vaping."
The Canadian Cancer Society has warned the trend threatens to hook youth on nicotine and "re-normalize" smoking. New Brunswick's deputy chief medical officer of health has called for a crackdown, and Nova Scotia has already said it will include e-cigarettes in laws banning indoor smoking and sales to minors.
Dr. Robert Strang, that province's chief medical officer of health, said he is not just worried about the devices leading young people to tobacco. Anecdotal evidence suggests existing smokers are using them to continue their habit indoors, negating the deterrent impact of smoking bans, he said.
"In the last decade, we've made significant gains, especially in youth smoking. We have a generation of young people growing up in an environment where non-smoking is much more the norm," said Dr. Strang. "We run a real risk of rolling that back."
There are signs, however, of a shift in opinion. The Canadian Lung Association said this week it is reassessing the strong stance against e-cigarettes it voiced just last year.
Mr. Damphousse , whose organization convinced the government to introduce graphic health warnings on cigarette packages, argued that any smoker who uses e-cigarettes is either consuming less tobacco or none at all, reducing his or her health risks either way.
In the U.S., regular tobacco sales continue dropping while those of e-cigarettes soar, suggesting consumption of the electronic devices "could surpass traditional cigs within the next decade," wrote analyst Bonnie Herzog of Wells Fargo Securities in a recent report.
Scientific research on their benefits and risks is accumulating, but is still limited. A recently published New Zealand trial of 657 smokers concluded that a "modest" 7.3% of nicotine e-cigarette users had quit tobacco after six months, compared with 5.8% using a nicotine patch and 4.1% employing an e-cigarette with no nicotine.
A U.S. government study published last September, meanwhile, found that the portion of Grade 6-12 students who had tried an e-cigarette doubled to about 6.8% from 2011 to 2012, although just over 90% had also smoked tobacco products.