There is an old saying when in comes to safety that "the best mask is one you'll wear". And we agree. However, if there are a couple of masks comfortable enough to keep on while you work, then you've got some choices to make.
For simple wood sanding, some folks recommend the old standard 3M 8210 particulate respirator. Lots of people would call this style a dust mask. Others would say that it's barely better than nose hair. It's an N95 which means it will filter out 95% of the particulate matter, which is certainly better than nothing. It's also cost effective at $12.85 per box of 20.
If you plan on doing lots of sanding, or are releasing more toxic or harmful particles (fiberglass, Bondo, varnish, paint - pretty much anything other than bare wood) you will want to create a better seal around your face. We like the 3M 7500 series for any work that is going to take you more than an hour or so.
The soft silicon face piece is inert and won't cause allergic reactions. It is also softer and more flexible than other masks making it ideal for jobs requiring you to wear it for long periods.
If you pair the 7500 series mask with the 3M 2091 P100 Particulate Filter you have a comfortable mask that is going to filter 99.9% of particulate matter down to 3 microns, which is darn small. In fact, this set-up will filter all sorts of stuff including the really dangerous sanded materials like lead and asbestos dust.
If you still have questions about dust masks and respirators, or are also trying to filter fumes or vapors, please don't hesitate to call us at 800-829-9580. We love to talk about this stuff.