Kiwi experts are slamming a study that says vaping could cause the same toxic damage to lung cells as traditional cigarettes

A new study suggests newer electronic nicotine devices may be no safer than cigarette smoking.

It directly compared new heated tobacco devices with vaping and traditional cigarettes - and found that all three are toxic to human lung cells.

Action on Smoking and Health policy analyst Ben Youdan says the study's methods are flawed and contradict other studies showing vaping is 95 per cent less harmful than traditional cigarettes.

Youdan says the research has many limitations, including being conducted in a lab rather than looking at "real world impacts."