One of the beauties of a PAPR is that you can have a full beard and you are still protected

You just have to make sure that you use the appropriate filter for what you are working with (i.e. the particulate filters won't filter out fumes). I do this full time and after about a month it looks like this:
When it gets like this I will use my shop vac to suck it out from this same side. But the inside is perfectly clean, never any dust in my nostrils or anything, love it!
Here's what I use, but PAPR system filters get dirtier quicker because they are constantly sucking air through jsyk