I've been reusing N95s for work. Most of the time, while in public outside, or even to pick up food, I'm just wearing a cloth mask. I'll wear an N95 for higher exposure activities, such as when someone is in custody in the car, at the hospital, or in the jail. Also try to use it when going into residences, especially if it's to deal with a volatile situation. So I'm not wearing them all day long. Sometimes it's not at all. Sometimes it's just one, or several short times per day. Sometimes it's prolonged for a few hours.
As far as trying to keep safe while reusing them, I am rotating 3 masks in 3 paper bags. If I wear a mask at all during a shift, the following day it goes to the back of the line and I select the next one. That way there's a minimum of 60 hours before I will use the mask again on a separate day (though some days I don and dof it several times). It's usually going to be longer than that between uses. I'm hoping this will make it relatively safe to reuse masks for a period of time. The question is also, how long before discarding? With the first batch, I did 2 months of rotating before discarding them and getting three new ones.