Health experts fearing a clampdown on e-cigarettes said that a UN report on the devices had exaggerated their health risk and underplayed their role as a safe alternative to tobacco.
Banned from indoor public spaces
The August 26 report by the UN's World Health Organisation (WHO) said governments should ban the sale of so-called electronic cigarettes to minors, warning they posed a "serious threat" to unborn babies and young people.
Read: Third-hand smoke bad for babies
The WHO report, to be considered at a global meeting on tobacco control this year, also said e-cigs should be banned from indoor public spaces.
But tobacco specialists, writing in the journal Addiction, said the report was flawed.
They said it was rooted in a bigger WHO-commissioned probe, the Background Paper on E-cigarettes, which they accused of bias and error.
"We were surprised by the negativity of the commissioned review, and found it misleading and not an accurate reflection of available evidence," said Ann McNeill, a professor at the National Addiction Centre at King's College London,
Vapour instead of smoke
"E-cigarettes are new and we certainly don't yet have all the answers as to their long-term health impact, but what we do know is that they are much safer than cigarettes, which kill over six million people a year worldwide."
Read: Passive smoking can kill you
E-cigarettes typically work by vaporising a liquid called propylene glycol, to which nicotine and flavouring have been added. The vapour is inhaled, like traditional cigarettes, but produces vapour instead of smoke.
The gadgets have been a huge hit with young people, who form part of a snowballing market worth about $3 billion annually, with more than 400 brands of flavours.
Supporters of e-cigs say the devices are a safer alternative to traditional tobacco, whose bouquet of toxic chemicals and gases cause cancer, heart disease, strokes and other ailments.
Opponents say the devices have only been around for a few years, and the long-term health impact from inhaling their industrial vapour is unclear.
Gateway to nicotine addiction
The WHO report acknowledged that e-cigarettes were "likely to be less toxic" than conventional cigarettes, but more research was needed.
Read: We try the e-cigarette
It also fretted that the proliferation of sweet flavours would become a "gateway to nicotine addiction" for the young.
The debate is unfolding as many governments are under pressure to impose regulations on e-cigs. At the moment, the worldwide situation is a patchwork, ranging from complete freedom of sale to bans on sales to minors or of e-cigs that contain nicotine.
The WHO failed "to acknowledge that e-cigarettes are not just less harmful than tobacco cigarettes but (also) that the concentrations of toxins are mostly a tiny fraction of what is found in cigarette smoke," the authors of the commentary said.
They also took issue with concerns about risks of passive inhalation, arguing that concentrations in vapour likely to be breathed in by bystanders "are too low to present a significant health risk".
And, they said, the review suggests e-cigarettes "inhibit smoking cessation, when the opposite is true."See breaking news and the hottest health tips before anybody else by joining South Africa’s biggest and best health community, like health24 on Facebook now!
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Image: Cheerful guy with e-cigarette from Shutterstock