Outside of the medical profession, I really don’t know.
And even there folks are reusing their masks.
Just look on YouTube for ways to decontaminate a used mask; there are docs around the country who are experimenting with this.
A true eye opener.
It seems a cottage industry in making masks has cropped up.
But there is no way of knowing efficacy of the product.
I’d wager the paint departments at home improvement stores are also empty of masks.
Maybe feed stores for agricultural spray protection?
Yeah, probably best to just wait for this to die out and then when it's all over, get a few masks for the next time something like this happens.