There's one big problem with wearing masks, take what I have as an example. I should point out at the offset I'm a keen DIY'er I also have a lot of hobbies/crafts I turn my hands to that involve chemicals, sprays, paints and other noxious substances that give off toxic fumes, hence I already have a large stock of masks & gloves which is the norm for me. So masks.. I believe I have three or four kinds ranging from simple cloth type to high end kinds with replaceable filters. That kind usually come with documentation indicating particulate absorption and whatever.
So what would any government recommended ? You could spend hundreds on protective breathing equ and of course there's no guarantee of anything. If they say wear this type only and you catch the dreaded pox who can you blame...they said it was alright and they let you down again.
I think the best thing if you have to go out or feel you really must, then wear whatever you feel ok with. Whatever you stick on your boat race make you look a pillock anyway plus bugger's up face recognition camera's