Which respirator filter to choose?

Since your enamel will be thinned with enamel thinner , mineral spirits or lacquer thinner, with lacquer commonly used to clean the airbrush, I would go with this one:

R51A (51475-00000)
Organic Vapors

Mike

Hi, Dave.
Mike is correct...or at least half-way so. You'll definitely need the organic vapor cartrtidge he suggests: R51A (5147-00000), but you're also going to need the paint prefilter and holder that fits over the top of the organic vapor cartridge to take care of the particulates: R9500R (51057-00000).

One other option is to buy the combination organic vapor cartridge with the P100 prefilter: R51HE (5148-00000). P100 is the new designation for the older "HEPA" acronym.

One important final thought: Make SURE you buy the cartridges that fit the manufacturer's mask. You can't put AO filters on a 3M, MSA, North, or any other mask. AO filters will only fit AO masks; that's true for every manufacturer of respirators.

Gip Winecoff

Mike V and Styrene,

Thanks for your' time. My mask is definitely AO. It's by Aearo and those websites are for Aearo filters. The filter Mike V recommended is the type that's already in my mask. I knew it was time to change filters and was wondering if I needed to upgrade.

Thank you,

Dave

Gip,

You mean that organic vapor cartridge will not trap paint particles?
That seems strange that it filters the organic part which is much smaller in microns I believe, and yet it won't filter the paint particles also. I never knew that.
I have always just used my MSA Comfo Elite mask with the organic cartridges on it alone. Is that also wrong?

Mike

Hi, Mike!
Yep, organic vapor cartridges will not filter out particulates. The reason it filters vapors is that the activated charcoal adsorbs (as opposed to absorption) the vapor molecules onto the surface of the charcoal. The charcoal is sized in the cartridge to provide the maximum surface area for adsorption to occur, and to provide the highest efficiency as it happens (makes the cartridge last longer). In addition the solvent vapor itself has to be polar so that adsorption can occur. Non-polar solvents (such as some freons, for example) don't adsorb well at all on organic vapor cartridges.
Likewise, particulates are definitely not polar, do not absorb onto the charcoal, and over time, work their way through the cartridge due in part to the negative pressure inside the respirator produced during inhalation.

So, in order to protect yourself properly against hazards associated with painting, you need both a paint prefilter and an organic vapor cartridge.

Hope this helps you some, brother!
Gip

Thanks once again for your much appreciated knowledge Gip.
I was not aware that MSA made a particulate filter that goes on along with the organic vapor one.
You learn something new every day.

Mike