What are the health risks attached?

Experts estimate 20,000 smokers who take up e-cigarettes are quitting smoking each year in the UK alone.

But vaping is not without its risks.

More than 805 cases of lung disease and 12 deaths in the US have been linked to vaping, according to the Centrer for Disease Control (CDC).

While the CDC is investigating the causes of this outbreak, they have advised people to avoid using vaping products, particularly those containing cannabis products.

In the UK, vaping has been linked to 200 health problems including pneumonia and heart disorders over the last five years, according to the Medicines and Healthcare Regulatory Agency (MHRA).

The MHRA said it is reviewing the information gathered in 74 separate “Yellow Card” reports filed by the public and healthcare professionals. But the watchdog emphasises the reports are not proof the adverse effects were due to e-cigarettes, but a suspicion by people reporting ailments that the device is to blame

In 2017, MPs began an inquiry into the health effects of vaping to see how the law could address "significant gaps" in existing research.

It has gone on to note “there is clear evidence that e-cigarettes are substantially less harmful than conventional cigarettes”. It added “there are uncertainties, nevertheless, especially about any long-term health effects of e-cigarettes, because the products have not yet had a history of long use”.

Public Health England (PHE) said most of the American cases of vaping related-illnesses were linked to people using “illicit vaping fluid” bought on the streets or containing cannabis products.

A PHE spokesperson said: “Unlike the US, all e-cigarette products in the UK are tightly regulated for quality and safety by the Medicines and Healthcare products Regulatory Agency and they operate the Yellow Card Scheme, encouraging vapers to report any bad experiences.”

Deborah Arnott, the chief executive of anti-smoking charity Action on Smoking Health (ASH), told The Independent vapers in the UK “should not be scared back to smoking by the news of vaping illness in the US”.

“Nor should smokers stick to smoking rather than switch to vaping,” she added. “It is essential, however, to only use legal vapes bought from reputable suppliers in the UK and not source illicit unregulated products over the internet.”