So I just got back from Home Depot where, in preparation for sanding, I bought a couple 3M "Woodworking and Sanding Painted Surfaces" respirators.

As I read the fine print now that I'm home it says "Helps keep non-harmful sanding dust out of your nose, mouth, and lungs during do-it-yourself/homeowner projects."

Great! It keeps the NON-HARMFUL stuff out, but apparently it just lets all the HARMFUL stuff right through!?

So, is this just a funny mistake on their labeling or did I buy the wrong kind of respirator? The one I got is one of those paper ones with some sort of filter material sandwiched between the paper and has a nice little exhalation valve on the front. It's clearly enough to prevent me from inhaling the sawdust - but after reading that I'm wondering if there's microscopic bits (you know, the *harmful* bits - lol) in the sawdust that will go right through this respirator?

Thanks...