The demand for face masks in the UK has risen amid fears about the coronavirus, despite expert advice casting doubt on their effectiveness.

There has been a “considerable increase” in demand at some pharmacies, with cases of Chinese tourists buying masks for their return to China, according to the National Pharmacy Association.

But experts warn there is “very little evidence” of the benefits of wearing face masks outside a clinical setting, and say that people concerned about the transmission of infectious diseases “would do better to prioritise good personal, respiratory and hand hygiene”.

Boots said there had been an increase in interest among customers, but was unable to comment on sales figures.

On the Boots website, a six-pack of “safe & sound” surgical face masks is sold out, with a note saying they will not be receiving any further stock.

Another product on the Boots website, a box of 50 masks, is also sold out and carries the same message about not being restocked.

Boots said surgical face masks were available to order in stores as a special line from the pharmacy counter, adding that it understood some customers may want them and so could speak to pharmacists who had the latest public health advice on coronavirus, and could look to order them.

The company said it had experienced intermittent supply of face masks and planned to restock them when possible.

Dr Jake Dunning, head of emerging infections and zoonoses, Public Health England, said: “Face masks play a very important role in clinical settings, such as hospitals.

“However, there is very little evidence of widespread benefit from their use outside of these clinical settings.

“Face masks must be worn correctly, changed frequently, removed properly, disposed of safely and used in combination with good universal hygiene behaviour in order for them to be effective.

“Research also shows that compliance with these recommended behaviours reduces over time when wearing face masks for prolonged periods.

“People concerned about the transmission of infectious diseases would do better to prioritise good personal, respiratory and hand hygiene.”

A spokesman for the National Pharmacy Association said: “A growing number of people are asking pharmacists for general advice about coronavirus, and preventative measures.

Empty racks in a branch of B&Q (PA)

“Pharmacists are emphasising the importance of simple precautionary measures like regular hand washing, in line with World Health Organisation guidance.

“Some pharmacies have seen a considerable increase in demand for face masks, including masks bought by Chinese tourists for use upon their return to China.

“However, the World Health Organisation and Public Health England guidance is focused on good hygiene and safe food practices, not masks.

“Therefore, pharmacists are reinforcing the message, to people wishing to purchase masks, that they should take the precautions advised by public health agencies.”

The coronavirus death toll, which has risen to 170, is currently lower than the 348 people who died in China from Sars.

The World Health Organisation (WHO) – which said the “whole world needs to be on alert” over the outbreak – is expected to reconvene its emergency committee on Thursday to decide whether to declare an international public health emergency.

The WHO’s advice for the public on coronavirus includes hand and respiratory hygiene, and safe food practices.

On face masks, a poster on the WHO website, under the heading Stay Healthy While Travelling, says: “If you choose to wear a face mask, be sure to cover mouth and nose – avoid touching mask once it’s on.

“Immediately discard single-use mask after each use and wash hands after removing masks.”

Meanwhile, a branch of B&Q in London appeared to be low on stocks of face masks, with racks empty on Wednesday evening.

B&Q has been contacted for comment.

And on, a pack of 12 “anti-virus” flu surgical face masks is sold out, with the online retailer saying they did not know when, or if, the item would be back in stock, although there were other masks available on the site.

An Amazon spokesman declined to comment.