black boogers are no good, either. And if you have a headache the same day or the next day, you will know you shoulda wore some lung/eye/skin protection. I have gotten headaches from applying/sanding body filler - but maybe I use too much wink

I only use the fresh air system when sandblasting or welding galvanized steel (which I almost never do).

I mainly use these: 3M 07192 respirator