Quote Originally Posted by myth View Post
I haven't tried it on a CBRNE mask yet, but I think the consensus is that it really only starts to interfere with a good seal when the beard gets too long. I imagine that if you keep the length pretty short and groom/trim around the neckline and sideburns it won't matter.

Granted, someone like a firefighter who wears a mask very frequently may care a lot more about exactly how good the seal on a mask holds. Someone like me....I've only ever worn the CBRNE mask in order to do the fit testing. I have borrowed airpacks from the FD everyone once in a while for bad decomp death cases in a confined space, but that's more about keeping the smell out than anything that's likely to hurt me by breathing in.
Yeah, and I just heard from a friend who's a firefighter that the more modern masks are pretty much "positive pressure", so it's more a matter of "good air" leaking out than "bad air" sucking in.

So, yeah, probably only in the case of a "wild beard" in a truly hazmat environment...