Just A Word of Caution
To all.
While the filtered breathing rigs are fine, they are no substitute for a properly operating dust collection system and air cleaner.
The basic premise of getting the dust at the source remains the overriding principal. The respirator may clean the air you breath while you're using it, however the fine particles of dust produced will permeate your clothing, and will hang in your shop air for many hours. A slight air movement and even walking through your shop will raise an invisible cloud of dust that you will be inhaling. As soon as you take the mask off, or walk back into your shop "unprotected", you've negated almost all of the benefit unless you are also doing everything you can to eliminate the dust in the room.
My ENT doctor handed me a surgeon's disposa-mask to use stating it was all I needed provided my DC and air cleaner were running.
PS to Joe: Learned a simple rule about bag DC's. If the bag is fully inflated when your unit is operating, then the bag is too small for the unit and you're loosing air flow to a useless restriction. This pretty much takes in every new DC being sold, regardless of its bags' rating. My pictured system moves that big bag, but it still has creases and folds showing during operation. That insures that I've got maximum throughput with no loss of suction to back-pressure.