Hey guys I was curious if anyone that has experience with various composites can chime in on the potential for skin irritation either in raw material form or during maintenance (sanding) and just all around.
What I am experienced with would be fiberglass and related splinters / irritation there so I’m familiar with that as a “baseline”. However curious regarding Innegra basalt (assume the Innegra is pretty tame, but unsure of the basalt) and carbon and Kevlar materials. How would these materials compare to fiberglass in this regard?
Thank you for any insight!
Both polyester/vinylester and epoxy are irritants to the skin in the liquid form, though epoxy is the worst. Many people who work with it a lot become sensitized to it and have to stop. Always wear gloves when working with epoxy and don't get any on your skin. After the resins cure, they are for all practical purposes inert and shouldn't be a problem sanding other than causing dust which can clog things up like lungs, so respirator recommended, or do it all wet sanding(?). There will be reinforcing fabric particles generated if you sand a cured laminate.
Glass is a mineral and breaks. You don't "cut" it, you break it, and micropieces fly off to increase irritation. It is just like working with fiberglass insulation. Itchy stuff, both E-glass and S-glass. Carbon is the same way, and conducts electricity to boot, so can theoretically increase irrtation because it transfers nerve impulses, though I seriously doubt it's a big factor. Basalt is just silica again. It's supposed to be a lower cost alternative to S-glass. Glass is silica. Essentially the same stuff. Basalt breaks like glass, makes microparticles like glass, etc. I don't think there's enough iron in it to conduct electricity though.
The plastic synthetics like nylon, Kevlar/Twaron ("aramid" there are other manufacturers of this, but I don't know if they have any real market share?), Innegra, Dyneema, Spectra, dynel and diolen, and a few others are all "softer" plastics and pretty non irritating. To my knowledge they are also nontoxic. Breathing the dust would just clog you up, not toxify you chemically (or shouldn't?)
Fillers for resins like microballoons, slippery graphite might be a mixed bag. They're all powders, which could irritate if inhaled. Glass microballoons could irritate with the "breakage" of individual bubbles when sanded after cure, but if they're used with fiberglass. Thixotropes, Cab-O-Sil is one brand name, are thickeners for resins that need it. It depends low-level hydrogen bonding for its properties. It can be easily stirred at lower concentrations, when the resin is in motion because those hydrogen bonds break and allow movement, but when motion ceases, they tend to grip again, sort of freeze up (temperature not involved), and the resin sort of stiffens up and will more easily stick to vertical surfaces without running down the sides. Most home builders just use it to make a putty for filling, and this property is lost in that situation. As a powder it's not a skin irritant at all because the silica in it isn't exposed, is coated with something that prevents that, but don't breathe it as it can really clog up the lungs. Pigments would depend on several things. The powdered graphite for slippery-making is a form that shouldn't irritate unless inhaled. "Carbon fiber," the reinforcement coverd above, is another form of graphite that is irritating though. Lots of forms of carbon, though we only use a couple of them. I'm pretty sure that most pigments today are relatively nontoxic (little or no lead in them for instance? "Red lead", which is lead tetraoxide, is likely not used commercially to make red pigment -- e.g. for paint -- any more? At least not legally?) but many pigments come as liquids or pastes and such are "dispersed" (suspended) in a resin, notably polyester or epoxy resin. That epoxy can be sensitizing as mentioned above. Polyester, too, though it's far less likely to be a sensitizer. Can happen. Users of pigments would want to match the pigment's dispersant with the resin system they're using for best result, though a pigment in polyester wouldn't degrage properties that much as so little pigment is usually used in a project.
What am I forgetting? It's been a few years since I've dealt with much of this stuff. Wood is relatively nontoxic, but I know a guy who built a cedar stripper and turned out to be allergic to cedar dust when sawing and sanding strips. He completed the boat but sneezed his way all the way through it. It happens! He hasn't built another one.
Good luck with the projects.
