Prime Minister Boris Johnson has said face coverings worn by the general public “will be useful” as the UK comes out of the current lockdown.
The Scottish government already recommends people use face coverings when in shops and on public transport.
The World Health Organization (WHO) currently says only two groups of people should wear protective masks, those who are:
It says medical masks should be reserved for healthcare workers.
Masks are not generally recommended for the public because:
But that doesn’t mean they have no benefit at all for the general public – it’s just that the scientific evidence is weak.
The WHO says countries must weigh the risks and benefits when it comes to advising the whole populations about wearing face coverings.
The European Centre for Disease Prevention and Control agrees that medical face masks should be prioritised for healthcare workers.
But it says non-surgical face masks might help stop the spread of coronavirus by people who are contagious but have no symptoms (known as asymptomatic transmission).
Scientists in Singapore suggest that risk is especially high in the 24-48 hours before an infected person is even aware they might have the disease.
Coronavirus is spread by droplets that can spray into the air when those infected talk, cough and sneeze. These can enter the body through the eyes, nose and mouth, either directly or after touching a contaminated object.
The Scottish government’s updated guidance is not compulsory and suggests people use cloth coverings, such as a scarf, rather than “medical grade face masks”. Face coverings should not be used for children under the age of two years, according to the guidance.
Advice for England, Wales and Northern Ireland has not changed and masks have not been recommended.
UK government ministers have previously raised concerns about the evidence and whether the move might result in shortages of medical face masks for the NHS.
On 18 April, more than 100 doctors wrote a letter to The Times saying they were “alarmed at official inaction over the need for the public to wear homemade face masks”.
And London Mayor Sadiq Khan has urged people to use non-medical face coverings, such as a scarf or bandana, when social distancing is not possible.
On 30 April, during the government’s daily coronavirus press briefing, Mr Johnson said face covering would give people confidence that they can go back to work once the current lockdown measures are eased.