Electronic cigarette users are inhaling potentially dangerous levels of a synthetic cooling agent used to mimic mint and menthol flavours, warns a new study. Little is known about the content of synthetic coolants in e-cigarettes or their health risks, yet that hasn’t slowed their popularity, with smokers especially keen on minty or menthol flavours.
The research revealed that e-cigarette makers are using the synthetic agents WS-3 and WS-23 in their products at levels higher than what the World Health Organisation considers safe. Suppliers have recently begun marketing synthetic additives that provide the cooling effect without the minty flavour.
The research from Duke University School of Medicine in North Carolina was presented at the American Thoracic Society’s (ATS) international conference in San Francisco. Professor Sven Jordt, author of the study, said: “In a prior study we discovered that a synthetic cooling agent, WS-3, was added to Juul electronic cigarettes marketed in Europe.
“Juul was the most popular e-cigarette brand at the time. This led us to explore whether synthetic cooling agents are also added to electronic cigarettes marketed in the United States.”
The professor, who works in anaesthesiology, pharmacology and cancer biology at the university began the study with his colleagues searching for terms like kool/cool and ice on websites that sold e-liquid and looking to see if companies sold the cooling agents WS-3 and WS-23. They focused their research on both the ice and non-ice varieties of Puffbar, the most popular brand in the US, which was designed as a disposable e-cigarette to evade the Food and Drug Administration’s regulation of ‘pod’ devices with exchangeable cartridges like Juul.
By using gas chromatography/mass spectrometry to identify substances within samples the team was able characterise e-liquids and synthetic coolants They then calculated the margin of exposure (MOE) to determine the risk of synthetic coolants in e-cigarettes.
An MOE of 100 means the user’s exposure is 100 times lower than levels proven to cause toxic effects in the organs of animals. The scientists detected WS-3 in 24 of the 25 refill e-liquids they identified. Nearly all (13 out of 14) disposable Puffbar flavour varieties contained WS-23, with five of 14 also containing WS-3, in both ice and non-ice flavours.
Synthetic cooling agents were found not only in mint- or menthol-flavoured products, but in fruit- and candy-flavoured products, including Puffbar and other disposable e-cigarettes. Puffbar markets flavours such as Mango, Vanilla, Berry and many other sweet flavours popular with young people.
Scientists studying harmful substances know that MOE below 100 indicates increased risk. Alarmingly, MOEs for WS-23 in 11 out of 13 Puffbar products were less than 100 whether the team modelled for occasional or heavy use.
Dr Jordt said: “When the MOE is below 100, regulators such as the FDA or World Health Organisation should review the safety of the product and advise manufacturers about steps to make the product safe to use. Our measurements and calculations demonstrate that e-cigarette users inhale WS-3 and WS-23 at levels higher than those considered safe by WHO, with the potential to cause organ toxicity.
“Regulators such as FDA should consider reviewing product safety of Puffbar vaping devices and the e-cigarette refill liquids we tested. WS-3 and WS-23 are regulated by the FDA as food additives, but not for inhalation. E-cigarette manufacturers are ‘flying blind’ by adding these chemicals.”
In April 2021, the Biden Administration announced its decision to ban menthol cigarettes and flavoured cigars. The ATS said: “Flavoured tobacco products have been a key strategy in Big Tobacco’s marketing arsenal to initiate smokers at an early age.”
