I do a lot of grinding of metal and wood in my work, and after a few days, my respirator gets pretty dusty and dirty. You should be changing cartridges regularly, but I like to clean out the entire respirator every couple weeks too.
It's pretty simple as long as you remember what parts come off and where they go back on, and only takes maybe 15 minutes. I have a 3m half-face respirator, so it might be a slightly different process for different brands/models.
Step 1: What You Need....
You can get all the supplies at any drug store:
- 70% Isopropyl Rubbing Alcohol
- A couple cotton pads (cotton balls might leave too much lint)
- A couple Q-Tips
- A Clean Jar Lid
.... and a well lit space to work. I laid out some paper so I didn't get rubbing alcohol on my coffee table.
Step 2: Taking Apart the Respirator
1 - Take off the cartridges. They usually twist to unlock for removal.
2 - Remove the strap. You have to tug pretty hard on the straps near the mouth piece, being careful not to break the straps.
3 - On the outside of the mask, remove the red "gasket" where the cartridges came off, and take out the blue rubber part covering the mouth piece.
4 - From the inside, remove the two yellow rubber flaps (they are attached at a center hole).
Step 3: Clean All Parts With Alcohol
5 - Pour some of the rubbing alcohol into the clean jar lid - this way you won't contaminate the whole bottle of alcohol.
6 - Use the cotton pads and Q-Tips to wipe down the inside and outside of the rubber mask, all the gaskets and rubber parts you took off, and the plastic mouthpiece that attaches the straps to the mask. (This part of my mask was particularly dusty and dirty.)
7 - When everything has been cleaned off, put everything back together in the reverse order that it was taken apart.
TIPS: Always use the right cartridge for the job (particulate vs. organic vapor vs. chemical), change your cartridges regularly, and store your respirator in a clean ziplock bag when not in use!