I just bought a new paint mask from Amazon.  Sprayed some 2K yesterday with a Pre-val, had a heck of a time with the no-longer-stretchy strap that goes behind my head, and decided it must be time.  HA!!!  Got to thinking about when I bought the beast, and realized it was 1977!
I know that because it was the mask I purchased when I went into the crop dusting business!  Wow, just how negligent can an old dude be?

Thing is, it wasn't a full face mask, but I used goggles for the glasses protection. HA!! again!  even after only spraying a little spot repair with the Pre-val, when I was done I could still feel a gritty texture on the back of my lenses.  That stuff goes everywhere.  The new mask is a full face mask this time.  (Now I'm heading out to the shop to wash my lenses with acetone to remove the grittyness.)  It works well, I've had to do that before.

So guys, check your mask out and think of the last time you replaced the filters, it's all in the interest of good health and a long flying career.