Doctor Hilary Jones has issued warnings on how to wear face masks correctly and what to do with them over 'contamination' fears.
The wearing of a face covering has been compulsory in shops since the summer, with a more recent development being the need to wear them in hospitality venues when being shown to your table or going to the toilet or leaving the premises.
The surgical blue disposable mask are the coverings favoured by many Brits but GMB and Lorraine health expert Dr Hilary said people need to be more mindful of how long they wear them for.
He began: "It has always been the case that one of the criticisms of mask wearing was people not wearing them correctly.
"And actually you almost need a degree in microbiology to wear a face mask correctly.
"It has to be sterile to begin with and it needs to be kept sterile."
Moving onto concerns about potential contamination, Dr Hilary added: "You should not touch it because this could contaminate it.
"If you wear a disposable mask, keep it for three hours, chuck it away and wear the next one.
"Be careful when you are putting it on - wash your hands etc.
"If you are using a reusable one, wash it on 60 degrees with an ordinary washing powder."
Dr Hilary's advice comes after he urged against just wearing a face shield to protect against the spread of coronavirus after a study conducted in Japan showed they are open to the risk of droplets falling.
He said: "The visor might stop big droplets being projected forward from your mouth and nose but it doesn't stop downward movement of small aerosol droplets as a mask might be better at doing.
"I do think it's very uncomfortable wearing a mask for a long period of time hence people try to wear the shields.
"But if it's less effective we might have to think about using masks."
