The World Health Organisation (WHO) advises governments around the world to apply a "risk-based approach" and consider different factors - such as feasibility and the risk of exposure - before deciding whether to adopt the use of face masks or not.
And Foreign Secretary Dominic Raab told ITV News the UK government has made its decision, with face masks saved for those in hospitals, care homes and so on.
He said: “There’s a difference between masks which are used in a clinical setting for doctors, nurses, care home workers and face coverings - the kind of DIY cloth mask that someone might put together at home.
“In relation to face coverings, they don’t really have much of an impact in terms of protecting the person wearing it but they can provide an incremental mitigation of the risk of transmission to other people.
“So we will say from Wednesday, in areas where you worry that you may be enclosed spaces with other people or with other people not from your own home, that we will encourage people in those particular circumstances to wear a face covering.”
The use of a mask alone is not sufficient to provide an adequate level of protection, according to WHO advice.
Other measures such as physical distancing and hand hygiene should be adopted.
What are the pros and cons of face masks? And how should you wear one?
Advice to the general public wearing face masks when out in public varies from country to country.
For many countries in Asia, wearing a mask has been the norm since the outbreak of the disease.
Across the continent, face masks could be used as part of the coronavirus exit strategy.
With different guidance from different governing bodies, ITV News has compiled the different advice is from around the world and some of the key questions about face masks.
If you are healthy, you only need to wear a mask if you are taking care of a person with suspected Covid-19 infection.
You should wear a mask if you are coughing or sneezing.
Masks are effective only when used in combination with frequent hand-cleaning with alcohol-based hand rub or soap and water.
If you wear a mask, then you must know how to use it and dispose of it properly.
The mask should cover your mouth and nose and there should be no gaps between your face and the mask.
Public Health England (PHE):
A quote on the website says: “Face masks play a very important role in clinical settings, such as hospitals, but there’s very little evidence of widespread benefit from their use outside of these clinical settings.
“Face masks must be worn correctly, changed frequently, removed properly and disposed of safely in order to be effective.”
How do facemasks work?
Evidence suggests that some people with Covid-19 are contagious before showing signs of symptoms.
Some people with the disease may not show symptoms at all.
The disease is spread via exhaled droplets, so the mask can act as a way of stopping the disease being spread in the air, on surfaces and to nearby people.
The benefit of the mask is that it stops people who may have the disease from spreading it.
Are some face masks more effective than others?
In a nutshell, yes.
Those with ventilators can help filter air.
There are also single use masks, reusable masks, surgical and cloth masks.
Due to shortages in worldwide PPE, the European Centre for Disease Prevention and Control advised on April 6, 2020, that “the use of non-medical face masks made of various textiles could be considered, especially if – due to supply problems – medical face masks must be prioritised for use as personal protective equipment by healthcare workers”.
While cloth masks may not offer as much protection as surgical masks, the UK government says the NHS should be given priority as they are currently experiencing a storage of PPE, including facemasks.
Can a facemask stop me getting coronavirus?
The UK Government says the single-most important factor in stopping the spread of the disease is to maintain social distance of two metres between people.
A face mask is a preventive measure but not the be all and end all.
The WHO says masks are only effective when used in combination with frequent hand-cleaning.
They also warn that a face mask may lead to a false sense of security that could cause you to lapse on other advice that stops the spread of the disease.
You should also replace a mask with a new one as soon as it become damp and advises against reusing single use masks, WHO says.
It is important your hands are clean and you should avoid touching your face once the mask is on.
To remove the mask: remove it from behind (do not touch the front of mask); discard immediately in a closed bin; clean hands with alcohol-based hand rub or soap and water.
Coronavirus: Everything you need to know: