Walls and Ceilings - Dust mask question

Can anyone explain exactly how the single use disposable dust masks are supposed to function. Does the air actually permeate the paper? When I use one, its seems most of the are flows between the mask and the face, no matter how tightly I can make. When sanding drywall, I end up with alot of dust around this area also. Plus, the air fogs up my glasses and/or safety goggles.

Would also appreciate any recommendation for a reasonably priced reusable dust mask for drywall and insulation situations.

Thanks. Hope I've posted in an approriate place.

Get a respirator instead, the disp masks can be a pain, since you can't pull them tight to seal.

Usually the paper masks will form to your face fairly well - they just don't filter out everything. I use a charcoal respirator that works well. The instructions always say you shouldn't have a beard but I ain't shavin' :p . . . and it seals well for me:D

Cheap-o ones are usually junk. Here's a couple of my rules when it comes to dust masks.

#1: it MUST say N-95 compliant. This means it filters the majority of dust out. If its not N-95 (at a minimum), its worthless, IMO.

#2: it MUST have 2 rubber bands that go around your head... if they only have 1, they don't seal worth a darn and dust will bypass the mask.

#3: it should have an aluminum nose bridge that can be adjusted (molded) over your nose for the best fit

#4: I usually get ones that have the exhaust port on front (the little square plastic breather). I don't like hot air steaming my glasses up.