If you spent 20 bucks on a paint respirator, you should have gotten a cartridge with a prefilter. Sometimes you get what's called a combination cartridge that contains both a dust prefilter and organic vapor cartridge in one unit. The cartridge is full of activated charcoal and designed to remove organic vapors through the process of adsorption. The paint prefilter is designed to handle paint pigments and dust. The organic vapor cartridge will NOT remove dust particles; likewise, the prefilter will not handle any of the vapors produced during painting operations.
If you got the cartridge or prefilter wet when you washed the mask, throw them away and get new cartridges. Vacuuming the cartridges will not help. If you have washed the respirator and re-installed the cartridges, try this:
1. Inspect the respirator. Make sure the inhalation and exhalation valves seat well against their mounts, and ensure there is no dirt between the valve and seat.
2. Put the neckstrap on first, then the head strap. (BTW, you should not be wearing a respirator if you have a beard or other facial hair that interferes with the facepiece seal).
3. With the respirator adjusted to your face, cover both the respirator cartridge inlets with your hands. If your hands are too small, try a small plastic bag in each hand that will cover the inlet. Breathe in. The respirator should collpase slightly on your face. If there are any leaks around the facepiece, readjust the respirator, and try again. When you can take a breath and hold it for about 10 seconds without a leak, you have a good seal. This is called a negative pressure fit test.
4. Next, cover the exhalation valve and breathe out slightly. The facepiece should expand on your face, but air should not escape from around the seal. This is a positive pressure fit test.
5. Breathe normally. If you can't breathe, or if you encounter difficulty getting air through the respirator moreso than normal, the prefilter side of the cartidge is full and should be replaced prior to your next job.
6. Try spraying a little paint from a spray can in a fairly unventilated area. Assuming you still have a good face-to-facepiece seal, if you can detect any of the odors from the paint vapors, the organic vapor portion of the cartridge has reached the end of its service life, and needs to be replaced. If not, the cartridge still has some life remaining.
Let me know how it goes. If you have specific questions, please don't hesitate to e-mail me.
Gip Winecoff