I'm looking for a simple safety solution for multiple small projects that keep coming up. But it's not clear what safety mask and filters to buy.
For example, I read an article that states that I need an N95 mask for drilling thru brick:
Safety first! Equip yourself with goggles, hearing protection, leather gloves, and an N95 respirator. Brick and mortar dust contains crystalline silica, which will be airborne when you start to drill into brick. Inhaling just a small amount is enough to create a health hazard.
I also plan to do some very basic removal of black mold. (Not on walls, I noticed some small amounts in the grout of my bathroom.)
Again, I'd need a mask, I hear. How do I know what filters and mask to buy?
I'm thinking of getting a 3M respirator and then buying these filters. How do I know if these are the correct filters for the type of work I'm doing?
To be completely protected, a 
Best Answer
Respirators are more typically used for preventing inhalation of gaseous contaminants which aren't filtered by simple fabric masks. They force air through media which entrap those gases. While they will also catch particulates, they're usually overkill for situations with just that concern. In your case, both silica dust and mold spores are particulates, with no real gaseous hazards involved.
Masks are simple dust filters, and the N95 spec indicates the size of the particulate that will be protected against. Search 'N95 mask' and you'll see a plethora of inexpensive options to meet your needs. These offer the added benefit of not making you look like a CDC operative while doing simple home improvement work.
I'd look for one with dual straps (for better mask-to-face seal integrity), and the exhaust vents some offer prevent forceful exhalation from creating gaps at the face-to-mask seal by more effectively venting pressure.