IT is the smoking substitute that has seen people ditching the fags in their thousands, and has become a craze in its own right.

Thick clouds of sweet-smelling “smoke” have become the norm across the country, as tobacco has been swapped for a piece of technology, and even non-smokers have taken up this very 21st-century habit.

But now vapers have been left questioning the safety of the “saviour” devices after a man in America became the first in the world to die from using e-cigarettes.

The man, from Illinois, is thought to be one of nearly 200 people in the US to present to doctors with a breathing condition linked to the smoking substitute.

Officials said the patient contracted a serious lung disease after vaping, and died on Thursday.

It was later reported that the man’s death may have been linked to vaping THC – the high-inducing chemical in marijuana – mixed with other chemicals, though medics have yet to confirm what substance he was vaping.

The man is one of 193 people across 22 states who developed severe respiratory illnesses after vaping. However, experts say the clear common cause of the problems had yet to be identified.

Those affected are mainly men, aged between 17 and 38.

Robert Redfield, director of Centres for Disease Control and Prevention in the US, said the investigation into the death was “ongoing”, but added: “We are working with state and local health departments and FDA to learn the cause or causes of this ongoing outbreak.

“This tragic death in Illinois reinforces the serious risks associated with e-cigarette products. Vaping exposes users to many different substances for which we have little information about related harms – including flavourings, nicotine, cannabinoids, and solvents.

“CDC has been warning about the identified and potential dangers of e-cigarettes and vaping since these devices first appeared. E-cigarettes are not safe for youth, young adults, pregnant women, or adults who do not currently use tobacco products.”

Dr Brian King from the CDC’s office on smoking and health warned against thinking of vaping as completely safe.

He said: “There’s a variety of harmful ingredients identified, including things like ultra-fine particulates, heavy metals like lead and cancer-causing chemicals,”

King warned of the possibility that similar cases had been happening for a long time, but the connection between them had been missed, adding: “It’s possible that the reported cases could have been occurring before this investigation was even initiated.”

However, the president of the American Vaping Association, Gregory Conley, said he was “confident” the illnesses were being caused by devices containing cannabis or other synthetic drugs, not nicotine.

In Scotland, an estimated 290,000 people use e-cigarettes, with the UK the third-largest market in the world for the devices, behind the US and Japan.

According to the Scottish Government’s register, there are 1,276 shops open across the country selling nicotine vapour products (NVPs), 4,395 selling NVPs and tobacco, and 4,831 selling only tobacco.

Experts have been divided about the safety of vaping products since they first came to market in 2011.

NHS Health Scotland in 2017 stated there was “still a lot we do not know about e-cigarettes” and added: “They are not risk-free but, based on current evidence, they have a much lower risk than tobacco. We need to carry out research to understand these risks, but in the meantime we need to make the best use of the situation to reduce tobacco smoking further.”

Scottish ministers are currently considering whether to ban the advertising of vapour products entirely, including those which do not contain nicotine, while in the rest of the UK non-nicotine containing products are able to be advertised.

In February last year, NHS England said every smoker struggling to quit, and pregnant women should be encouraged to take up e-cigarettes. The body even encouraged allowing vaping in hospital wards and permitting patients to vape from their beds.

In July this year, two vape shops opened in hospitals in England. At the same time they introduced a £50 fine for anyone caught smoking on site.

Sandwell General Hospital in West Bromwich and City Hospital, Birmingham, both opened vape shops run by Ecigwizard, selling products such as Jubbly Bubbly and Wizard’s Leaf.

Experts from the University of Stirling, King’s College London, Cancer Research UK and the UK Centre for Tobacco and Alcohol Studies released a report for Public Health England last year suggesting e-cigarettes were helping up to 57,000 people a year to give up smoking.

The study also restated the claims that vaping is at least 95% less harmful than smoking, and increased users' risk of cancer by less than 0.5%. This is in comparison to those who smoke, whose chances of developing cancer are between 15 and 30 times more likely than non-smokers.

Smoking can also increase the risk of heart disease and heart attacks, while male smokers have a life expectancy 12 years shorter than non-smokers. For women, they can expect to die 11 years earlier than their non-smoking counterparts.