A: Find and contact your local 3M representative (or find them on the web). You can purchase a mask type that takes different types of cartridges, and you likely will need different canisters for the different uses you have. For simple dusts, you can use the paper filter types similar to what is used for medical purposes, although they’re not quite the same. 3M again, makes a fine one, an N95 type that also has an air valve on the front to make breathing easier, and which keeps it from fogging up your goggles. If you keep it in a ziplock bag when not in use, these inexpensive masks last a long time. But they are only for nuisance dusts, not fumes from soldering. For that, you’ll need something more thorough. Again, discuss your exact materials and needs with the 3M folks. They make a very extensive selection, and can tailor something to exactly what you need. And, on a good note, at least based on what the 3M people said at the SNAG conference, prices are lower now than they used to be, which is a good thing indeed.