They will, but you have to follow some protocols, like not having beard where the masks is supposed to seal around your face, not using it more than ~3 times (iirc), not trying to clean it (just let it rest for some days on a clean surface) and etc.
Basically always seal testing.
Also, iirc the N stands for not oil resistant, so any oil staining ruins it. I'd guess that includes sneezing on it.
SHIZAAA