iQOS may not be as harm-free as claimed, study finds

The IQOS system heats tobacco sticks without burning them, until they release nicotine vapour. Photo / Philip Morris

A new smokeless tobacco product marketed as being less harmful than cigarettes may not be as harm-free as claimed, according to a new study.

The study, published in today's Tobacco Control journal, found Philip Morris' iQOS could cause smokers to inhale more often and expose them to another toxic chemical.

The iQOS is a battery operated electronic device which heats tobacco sticks, rather than burning them, to produce a tobacco-infused vapour which can be inhaled.

The product is also at the centre of a legal dispute between Philip Morris and the Ministry of Health which claims the product is not legal in New Zealand because it is a tobacco product for oral use rather than smoking, since it is not ignited.

The University of California study found that, since the device could only be used for six-minutes before it needed to be recharged, it may cause some people to shorten the interval between puffs in order to make sure they did not waste any of the tobacco stick which could increase the possible toxic exposure.

But of greater concern was that the polymer filter melted slightly during use and released formaldehyde cyanohydrin, a toxic substance which could be fatal to humans. The compound is metabolised in the liver and broken down into formaldehyde and cyanide.

"This study has shown that the iQOS system may not be as harm-free as claimed and also emphasises the urgent need for further safety testing as the popularity and user base of this product is growing rapidly," the study concluded.

University of Otago public health and marketing Professor Janet Hoek said the findings led her to question whether it really was a "reduced harm" product as claimed by the manufacturers.

If users inhaled more frequently as it was suggested, it was likely they would "increase their nicotine intake and exposure to harmful compounds present in the inhaled aerosol", she said.

She said those who had tried unsuccessfully to quit smoking were better off considering e-cigarettes.

Auckland University National Institute for Health Innovation programme leader Associate Professor Natalie Walker agreed e-cigarettes were a better option for those trying to quit because they did not contain tobacco.

But, when smokers had tried repeatedly to quit, even using e-cigarettes, it could be a last resort.

"Heat-not-burn devices are not without harm. However, they are less harmful than smoking cigarettes [which have over 4000 harmful chemicals in the smoke]," she said.