E-cig flavourings 'can be harmful'
Flavourings used in e-cigarettes contain potentially harmful high levels of chemicals, researchers have warned.
Vapers have a vast selection of tastes to choose from, including m enthol, cherry, coffee and bubble gum, but they said that although the flavourings used are mostly the same as those found in food and have therefore passed safety tests, this applies to them being eaten rather than inhaled.
The study carried out in the United States analysed the chemicals used to flavour e-cigarette fluid in a sample of 30 products, and found a "significant" number were aldehydes - compounds which are recognised to be primary respiratory irritants.
Assuming a consumption rate of around 5 ml/day, as commonly reported on online vaping forums, researchers said e-cigarette users would be exposed to twice the recommended occupational exposure limits of benzaldehyde and vanillin.
The study quoted a recent report that found an "astonishing 7,764 unique flavour names" available online in January 2014, with 242 new flavours being added a month and sales occurring under 466 brands.
Researchers at Portland State University in Oregon said their sample represents a fraction of the e-cigarette products on the market.
"The array of e-cigarette products is vast and growing daily," they said.
"As such, this study was unable to provide a comprehensive overview of the levels of flavour chemicals in such products currently on the market.
"Nevertheless, the results obtained are likely to be similar to what a broad survey would have revealed, and in any case strongly suggest that very high levels of some flavour chemicals are undoubtedly present in a great number of the thousands of products currently available.
"Regulatory actions that should be considered include requiring ingredient identification, limiting levels of some individual flavour chemicals, and limiting total levels of flavour chemicals."
A separate study, which is also published in the BMJ, looked at the use of e-cigarettes in children in Wales.
It found 5.8% of 10 to 11-year-olds had tried e-cigarettes - far more than had tried tobacco (1.6%).
Amongst children aged 11 to 16, 1 2.3% said they had tried e-cigarettes
Only 1.5% - including 0.3% who did not smoke tobacco - reported regular e-cigarette use.
The study said there is evidence that e-cigarettes are being used by growing numbers of young non-smokers leading to " significant concerns that, if unregulated, and marketed to young people, e-cigarettes could seriously undermine the success of recent tobacco control strategies".
The authors added: "The carcinogens and other toxins within e-cigarettes are one concern; harm reduction arguments do not hold where e-cigarettes are used by young people who would not otherwise have been using tobacco.
"Furthermore, it has been suggested that e-cigarette use could act as a new gateway into nicotine addiction and tobacco use for young people."
They said the wide range of colours and flavours are likely to particularly appeal to young people, as has been the case with sweet-flavoured alcoholic drinks.
"To develop comprehensive prevention strategies, we therefore urgently need to better understand youth e-cigarette use, including how this relates to smoking."
Another recent study into the use of e-cigarettes by teenagers in the UK, by Liverpool John Moores University, found e-cigarettes were "strongly related" to drinking amongst teenagers.