The CDC (Center for Disease Control) recommend NIOSH approved N95 (95% filter efficiency when subjected to a 0.3µm MMAD Sodium Chloride particle challenge) like the 3M 8210 and the folding version 9210. I want to get some folding. They sell it in boxes of 20. Whatever the brand you get, it must be NIOSH approved and should be written on the package.

But I'm not getting these for the pandemic threat. It's more for short emergencies like a terrorist attacks or accidents where there could be dusts etc. or even just for working in a dusty environment.

I mean if the virus mutates and there's a real outbreak of human to human transmission it's going to last a couple of weeks or month and you'll have to stock up on more than 20 of these disposable masks and of course it's not going to be infallible, far from it. Or you'll have to shelter-in-place for a long time...

Frankie