Doctors and health academics from around the world are urging the World Health Organisation (WHO) to regulate the sale of electronic cigarettes, which are booming in an uncontrolled global market.
A US study has found the e-cigarette market has more than 500 brands and is expanding at a rate of more than 10 a month with the product often purchased online.
In a trawl of the internet, US researchers found that as of January 2014 there were 466 brands, each with their own website, and 7,764 different flavours.
E-cigarettes are battery-powered devices which heat a liquid, typically propylene glycol, to a vapour. The liquid usually contains nicotine and flavouring.
Supporters say the gadget can help wean smokers off conventional tobacco, whose bouquet of toxins has been blamed for the death of millions.
Health watchdogs are cautious, saying the long-term impact of e-cigarettes use is unclear.
Sydney health expert Simon Chapman says anecdotal evidence has been used to promote the benefits of the devices.
He says not enough is known about the potential side-effects.
“We need more than a feeling. We don’t proceed like that in the regulation of therapeutic substances,” he said.
“What we do is say: ‘OK, you reckon you’ve got something that does that, let’s put it to the test’.
“Provide all of the evidence to the therapeutic assessment panels and they’ll make up their mind if you’ve got evidence or [if] you haven’t.”
The US Food and Drug Administration (FDA) in April proposed barring sales to minors, placing the product on the same footing as tobacco in this regard.
Shift in e-cigarette marketing: flavour not tobacco alternative
“The number of e-cigarette brands sold on the internet is large and the variety of flavours staggering,” wrote the investigators from the University of California School of Medicine in San Diego.
Over the past two years, the market has been growing at an average rate of 10.5 brands and 242 flavours per month, they said.
The most popular flavour category is fruit, followed by dessert/chocolate, alcohol/drinks or snacks/meals, according to the study.
The study authors also noted a shift in e-cigarette marketing.
Older brands were more likely to claim e-cigarettes were healthier or cheaper than tobacco, or could help smokers kick the habit.
Newer brands, though, tended to shun references to tobacco and focused instead on flavours or models.
“It seems that new brands don’t want to be compared with cigarettes, which are associated with the image of cancer,” said Shu-Hong Zhu, director of the Centre for Research and Interventions in Tobacco Control in San Diego.
The new study was based on two searches of English-language websites at a two-year interval – first from May to August 2012 and then December 2013 to January 2014.
A separate study in the same journal reported that some 29 million people in the European Union had tried the e-cigarette, based on 2012 data.
It also found that most of them were smokers or would-be quitters.