Dust masks DO NOT cut it. Trust me, I know, I sell First Aid and Safety products for a living. READ THE MSDS (Material Safety Data Sheet) for the product and you’ll see that at the least an ORGANIC VAPOR rated cartridge is the minimum recommend by the manufacturer of the product. True, this is for the uncured “a” and “b”, but you can’t tell me with a straight face that resin is 100% inert after mixing, so assume the worst and BE SAFE.
The cheapie little masks from home depot only usually get a N95 rating at best, and that’s for the more expensive ones. Without fit testing, and the leakage you get around the mask with “generic” sizes, the masks really aren’t even that good protection wise. The really cheapies, well, lets just say you get what you pay for, a false sense of protection. We call them “comfort masks” for a reason in the industry, that’s all they are for, to give you some filtration and some comfort from airborne particles. N95 means, in the technical world of ANSI (American National Standards Institute) standards, that the “N” means it will filter ONLY non-oil particles, that oil particles will quickly degrade the rating, and the “95” means it will pick out around 95% of a given particulate size. A mask like this does nothing to filter out organic vapors or other toxic gases, and it still means you're getting 5% of the crud into your lungs.
*EDIT* For clarity: Mask vs Respirator: Masks are usually the paper disposable product you see everywhere, and respirators are the usually silicone form fitting shield you see with the cartriges that attach much like a gas mask. And no, surplus gas masks donÂ’t get you squat for protection. *End Edit*
What you really need, according to the MSDS, is a P100 organic vapor cartridge in a respirator, which is “P” all particles, and 99.97% filter rate, on a respirator that is properly FIT TESTED for your face so you do not have any blow by and are truly getting the stated filtering rate. You MUST change out you cartridges with the manufacturers spec, otherwise we’re back to that false sense of security. It helps to store you respirarator in a locker or a loarge zip lock bag between uses to keep the cartriges fresh.
An over the counter investment of around $30 is well worth your health and peace of mind. For that, you can get a decent quality half mask with suitable P100 Organic vapor cartridges attached. I pay, with my discount, around $10 for a good MSA half mask, which will last me practically forever, and another $12 for some VERY HIGH RATED, way overkill according to the MSDS for the Polytek Easy Flo product I use, P-100 Organic Vapor/Acid Gas/Ammonia cartridges which I keep in service only as long as the spec sheet allows or until I feel they are not working (odor, hard to breath, etc).
Personally, after thinking that, yeah, I won’t ever have a reaction to resin, and now when casting I do sometimes; I take EXTRA steps to protect myself. Before I start pouring now, I grease up with one of the commercially available “liquid gloves” on all exposed skin, open the door and turn on a fan to get the air moving. I still wear gloves as always, but now I make it a very large point to get any spilled resin off ASAP, and as soon as I’m done take a nice long shower and REALLY scrub down all my skin several times.
As far as sanding goes, I try to wet sand when I can when I’m building up here at home, a deep tray with water goes a long way to keep the dust down to zero. When I’m using bench tools to sand down large pour sprues or core out TIE hulls, I wear my respirator and put a fan on high blowing the dust away, and I “use the compressor and an air cleanup tool to “blow” all the dust off my clothes as soon as I’m done. I leave my mask on until the air is clear, and if you run a shop vac to pick up after yourself, wear the mask while you are running it as it’s not HEPA rated and is tossing back some of that resin in the air. Cured resin is better in that your absorption through the skin is probably very miniscule since it is no longer liquid, and by protecting your lungs with a respirator you are really minimizing the exposure. But, it goes without saying, don’t eat drink or smoke until you wash up, and do this if not outside then in a garage or other area that you don’t live in that you can ventilate well.
Everyone has different tolerance “thresholds”, and until you overdo it like I have once or twice and “paid the price” with nasty rashes and sometimes some respiratory distress (real fun when you have asthma already), you won’t know what that is. And, it is cumulative damage to your body, and until you detox you’re super sensitive, and no matter what your threshold is lower for the next time and you did some damage, permanently.
For the minimum exposure of cured resin though sanding for a hobby only, donÂ’t take the chance, buy a quality respirator that fits, and USE IT. You only get issued one body in this life, and you need to protect it as much as possible.
Oh, and resin is not near as bad as asbestos, as it’s not listed as a know carcinogen (at least the type I use), but it does have a residue as a plastic that can build up on you lungs like asbestos that is very hard for your body to expel. Asbestos is dangerous and causes cancer mainly because it “burrows” into you lungs and other organs and your body doesn’t have a way to get it out, and your body winds up leaving some form of scar tissue around the fiber to isolate it from the rest of your body and to keep the sharp particle from doing further damage.
Hope this helps,
Ryan
