(social distancing and masks could become a racist/cultural issue).
To wear a mask it has to by Law be specific to the task it is designed for. Health and Safety - DH has been explaining.
So if the mask is to be safe either for the wearer or for those around him/her, it has to be fitted by someone who knows a) how the mask is designed to work and b) for which purpose.
Once only masks such as we see in the Hospitals are throw away and usually clip behind the ears with elastic. More industrial masks are fitted differently. For those in the Fire Surface or Emergency Cave Teams or in the Chemical Industry [which is where we come in], they are complete masks covering the head, neck, face, shoulders ......... with visors . Nothing in, nothing out. These are in daily use which the public don't often see.
If a mask is to be used correctly then those wearing beards will have to shave in order for a snug fit. This becomes a problem in many communities where beards are part of the culture and a form of respect. One Doctor has already shaven in order to wear his mask correctly to provide protection for himself and any patient he comes into contact with.
If the NHS has had problems sourcing enough protective clothing then I think it's a long reach to insist that the public has to wear masks. Where does it stop? On whose advice?
I do wonder if, now that the Chinese have arrived in London to offer advice, whether this is being muted by them having had experience sooner than the rest of the World as to how masks assist.