I agree with Gary's recommendation for a half-mask air-purifying (negative-pressure) respirator equipped with dual organic vapor/P95 cartridges. The organic vapor portion of the cartridge contains an adsorbent material that will filter out most organics and the P95 will filter out any particulates and mists.
If you experience eye irritation, then you may need tight-fitting chemical goggles along with the half-mask respirator. Its a challenge to find goggles that a) won't fog up and b) will achieve a reasonably good fit along with a half-mask respirator. If need be, I can provide you a recommendation with chemical goggles that should work while wearing a half-mask..... The most important thing is to have a good face to mask seal with the respirator.
Alternative to Half-Mask Respirator and Goggles:
Buy a full-facepiece twin cartridge respirator such as in the 3M 6000 Series. These are much pricier than a half-mask respirator, but you get eye/face protection and they are much more comfortable to wear for extended periods. Takes the same filters and cartridges as the 3M half-mask as they both have the Bayonet fittings.
Size: With respirators, one size does NOT fit all. You might need a Large, you might not. Here at Eastman, I am fit-tested every year with a medium 3M 6000 Series half-mask respirator and a medium MSA (Mine Safety Appliances) Ultra-Twin Full-facepiece cartridge respirator. I've been told that I have a large head....
While employees included in a company's Respiratory Protection Program receive annual fit-testing (with a device that can measure both inside and outside a respirator to quantitatively evaluate whether is a good seal) and training (per OSHA requirements), I'm not sure what members of the public at large are to do to ensure they're wearing the proper size respirator - aside from my below suggestion:
At minimum, there are simple
Negative and Positive Pressure Fit-Checks that should be followed each and every time you don (put on) a respirator to ensure a proper fit. Here a couple of nice videos.
One last thing, to achieve a good seal between your face and respirator,
be clean-shaven.
No beards, goatees (a modest Soul Patch is OK), civil war era muttonchops, Lincoln-esque Chinstraps, long-ass mustaches, etc. that will break the seal along your chin. if you don't have a good seal, contaminants will get in... At my plant, we fit-test over 3,000 employees annually and there is typically bitching and moaning when Deer Season comes around and guys want to get beardy. If you want to keep your Fu-Manchu or whatever, consider a 3M Powered Air Purifying Respirator or "PAPR". They still have a cartridge or filter but you wear it on a belt around your waist along with the battery pack and blower. PAPR's are Positive Pressure Respirators (like supplied-air respirators), but you're not tethered to an air supply hose. No need to be clean-shaven or do fit tests or fit checks.
I am an Industrial Hygienist (for 23 years) with Eastman, so I routinely evaluate/measure airborne chemicals (listed on MSDS's) during the performance of tasks (e.g., spray painting) or over a person's workshift so as to determine whether their "exposure" exceeds OSHA limits (or other established guidelines). If it does, we recommend appropriate respirators, but
first recommend engineering controls (ventilation) to reduce airborne concentrations.
Do your paint spraying in a well-ventilated area if at all possible!