G10 (And Micarta fumes) + Respirator filter question

[mgysgthath]

Hi there,
I'm a relatively new maker, but I've accumulated quite a few good tools etc and done a large amount of reading. I still have some practical hands on to do of course.

Anyway I have some G10 slabs and I can easily cut them etc, but my question is about respirators.

I have a 2 cartridge based half face mask respirator which game with NIOSH P100 filters that are for asbestos/lead fumes. These things can be changed with any of 10-20+ different ratings of filters. The company was no help in suggesting any, they basically said I'd need to gather an AIR sample and have it analyzed in a lab. Well I don't really have that option, so I'm hoping you more experienced makers have some knowledge on the subject.

So G10: It is fiberglass based, and the fibers are bad. My logical thought is these are particulate, so anything that blocks lead fumes (and asbestos particulates) should also block fiberglass particulates. Or am I incorrect in this?

Micarta: Not at all concerned with the particulate matter, even a cheapo mask keeps that at bay. However the fumes it lets off when grinding are extremely awful, and I can't imagine it's good for me. I have yet to try this new respirator with either situation, but I'm hoping to get some info before I put myself in a potentially dangerous situation.

My plan as of now is to try each and if I smell any fumes, I know it's not protecting against that much of it. But I feel that it will probably work fine for the particulates in both cases. I also plan to cover any exposed skin possible when using the G10 as I don't want those fibers in my skin.

Any info is appreciated,
Thanks.

 

[Patrickknives]

I have wondered about the fume questions and I never felt that there was a volitile that would be release when working micarta. The two volitile ingredients phenol and formaldehyde as fused together to make the resin. There is really no way to seperate them. The dust is a different question, it is nasty and gloves are a must. I also wet my micarta as I grind just like it was a piece of steel. This prevents dust around the grinder and in the shop. I have a dust collector but no way is it near 100%. Bottom line a good respirator for fine dust partical is all that is needed.

This product is a thermostatic composite consisting of a cured phenol-formaldehyde on a cellulose substrate. OSHA PEL and ACGIH TLV have
not been established for this material. Formaldehyde has been designated a carcinogen on the following lists: NTP/IARC/OSHA
Precautions must be taken when formaldehyde is present In the air at concentrations greater than 0.1 ppmas described in the standard.

http://www.norplex-micarta.com/products/28/96_Norplex-Micarta_MSDS-NB510A.pdf

Micarta MSDS, recommends dust filter mask only

 

[Nathan the Machinist]

I believe it is not too difficult to generate free formaldehyde when cutting and especially grinding micarta. And phenols aren't real good for you either. I'm not sure about the chemistry involved, but I do know that in some thermoset polymers, there is generally some percentage that does not "cure" (chemically locked through cross linking). I'm thinking specifically of epoxy, rubbers, and thermoset polyurethanes but I suspect the same is true with phenolic. Regardless, I've processed an awful lot of it (thousands of pounds) and the fumes make my eyes water and throat hurt and make me feel sick, so I now take substantial measures to minimize my exposure to the fumes. I keep it wet, I filter my sumps, I move away while it is machining (if I can) and I keep lots of fresh air moving through.

I processed some really thick stuff earlier in the year that was old old stock. The outside was dark brown and the inside was a bright yellow, it actually looked like a smoked cheese. This stuff was so potent I actually dumped a sump after machining it stunk so bad. I worry a lot about things like cancer and other diseases because people like me (and probably you too) who are exposed to these sorts of things over long periods of time frequently die before their time.

 

[mgysgthath]

Thank you for the replies.. Micarta doesn't worry me as much as G10, I can use a strong fan to keep the fumes away if the P100 filters on the mask won't cut it I suppose. Keeping it wet is a good idea, though I wonder about the belt dragging water into the grinder and rusting things; I'm gonna give it a try though for sure.

I guess what I'm really wondering is about respirator filter standards, and which if any are capable of blocking however many microns small the fumes are. But I think I'm going to have to try and see.

Nathan, I'm guessing a sump is part of a milling machine? I've never had the pleasure of working with one as of yet.

 

[TomTerrific]

I was an industrial hygienist way back when. Filters that take care of asbestos and lead won't get gases as you note. The dealers don't want to assume the liability so they won't tell you anything, and, when they do, use weasel words.

I would suggest searching for the decomposition products of the various products and go from there. I am not a polymer chemist, but I would be extremely surprised if there were any free formaldehyde and/or phenol in the materials. That is not to say none can be generated by the grinding process. Both, I believe, have fairly low odor thresholds and distinctive odors, but don't quote me on that.