Vaping companies could be asked to fund research into the health effects of flavoured liquids used in e-cigarettes under plans being considered by the UK’s medicines watchdog. The proposal, outlined to the Observer by an expert on tobacco control, comes as studies link e-liquid flavours such as mint, creme brulee and cinnamon to heart and lung problems.

Last week, the US announced a ban on most e-liquid flavours over fears that vaping has reached epidemic proportions among teenagers. But this ban applies only to vape “pods” – individual cartridges used in vape pens to deliver flavour popular with young people – and not to the larger “tanks”, and some experts worry that users will simply switch.

Professor John Britton, director of the UK Centre for Tobacco and Alcohol Studies at Nottingham University, who sits on the Medicines and Healthcare Products Regulatory Agency (MHRA)’s panel on e-cigarettes, said flavours were really important to smokers: “If you restrict the flavours, you may restrict the tolerability of vaping to people trying it for the first time, but you will also lose an awful lot of smokers.”

There is no way of saying that cinnamon is safer than orange. I don’t see how you draw the line John Britton, health expert

The US’s shift has invited scrutiny of the UK’s stance on e-liquids, which has been criticised by bodies such as the European Respiratory Society Tobacco Control Committee. An expert committee on toxicity will report to the Department of Health in the spring but it is not expected to recommend that flavours be banned. Alternatives to a ban are being explored, Britton said. “One suggestion is for vaping companies to club together to get flavours licensed. This would give these companies a marketing advantage and perhaps set their shareholders’ concerns about future litigation at rest. Most vaping companies are small, and can’t afford the time or investment in to get a flavour through the medicine licensing process.”

He continued: “The only way that could happen would really be if a number of companies grouped together and applied for a common licence for a particular flavour or set of flavours. Then you would have something that would be safe to medicinal standards and at that point you can stop worrying about it.”

Some of the larger vaping companies are owned by big tobacco, which has a history of manipulating scientific evidence. Measures would be needed to ensure any flavour testing was carried out by independent experts selected by the relevant health bodies. A new testing regime could see the end to certain flavours.

“If you look at the list of flavours that are available in the UK, it’s huge,” Britton said. “It would be very hard to argue that all of those are necessary but how do you then say ‘this one is OK and this one isn’t’? You could say ‘OK, no flavours’ in which case you will make vaping unacceptable to most vapers. Or you could say ‘we’ll allow a limited list of, say, half a dozen flavours’. But how do you decide what those should be? There is no way of saying that cinnamon is safer than orange. I don’t see how you draw the line.”

Compared with the US, the UK heavily regulates the promotion of e-cigarettes to young people. However, the number of young users in the UK has increased in recent years.

A UK Vaping Industry spokeswoman said: “All nicotine-containing flavours are submitted to the MHRA for testing to ensure that no toxic compounds are formed in the process of vaping and we work vigorously to make sure that non-regulated products do not enter the UK market. We work collaboratively with UK regulators to ensure that the highest production standards are adhered to, not only over the manufacture of vaping equipment and liquids, but also to ensure full compliance by our members with the strict rules that forbid sales and marketing aimed at under-18s.”