Scimex: A US study has found that a number of flavour chemicals in e-cigarettes
exceed recommended amounts and may irritate the airways. They report
that many e-cigarette smokers are inhaling twice the recommended amount
of certain chemical flavourings, and that six of the 24 flavour
chemicals revealed in their analysis are known airway irritants.
The levels of chemicals used to flavour some brands of e-cigarette
fluid exceed recommended exposure limits and could be respiratory
irritants, in some cases, suggests research published online in the
journal Tobacco Control.
The electronic cigarette market has
developed rapidly in recent years, with global sales in 2014 estimated
to be in the region of US$7 billion, but the health implications of
vaping remain hotly contested.
Artificial and other flavourings in
e-cigarettes are mostly the same as those used in food and
confectionery manufacture, and are therefore often represented as safe
by e-cigarette manufacturers.
But as the US Flavor Extracts
Manufacturers Association (FEMA) has pointed out, this safety relates to
exposure through eating, and not inhalation. And the ingredients listed
on the product labels for e-cigarettes rarely include the chemicals
used for flavouring.
The researchers therefore set out to find out the levels and type of
chemicals used to flavour e-cigarette fluid in a sample of 30 products.
These
included two single use disposable brands in five different flavours of
tobacco, menthol, vanilla, cherry and coffee; the same flavours in
refill bottles; and additional flavours of chocolate/cocoa, grape,
apple, cotton candy and bubble gum in refill bottles.
The
flavouring chemicals totalled more than 1% by volume in 13 of the 30
liquids analysed, levels greater than 2% by weight in seven liquids, and
levels greater than 3% by weight in two products.
Seventeen of
the products contained the same vanillin or ethyl vanillin flavourings,
suggesting that a small number of chemicals are particularly popular
with manufacturers and users.
And many of the 'tobacco' flavoured fluids contained chemicals used to flavour confectionery.
Six of the 24 compounds revealed in the analyses were aldehydes, compounds recognised to be primary respiratory irritants.
Using
a consumption rate of around 5 ml/day, as commonly reported on online
vaping forums, vapers would be exposed to twice the recommended
occupational exposure limits of benzaldehyde and vanillin with the
products tested, say the researchers.
"And toxic degradation products may be produced by reaction of the
flavour chemicals at the high temperatures present during vaping," they
caution.
They admit that their sample represents a fraction of the e-cigarette products on the market.
But they say: "Nevertheless, the results obtained are likely to be
similar to what a broad survey would have revealed, and in any case,
suggest that very high levels of some flavour chemicals are undoubtedly
present in a great number of the thousands of products currently
available."
Regulations are needed, they argue. These should
include compulsory ingredient listing, limiting the levels of certain
flavourings, and limiting the total permissible levels of flavourings,
particularly as there is some concern that flavoured products might make
e-cigarettes more attractive to young people, they suggest.