I've been looking into this material due to the really nice surface finish and clean look (actually purchased some already 😅)
However I recently came across a video by CNC kitchen where he raised some potential health concerns relating to the fibers specifically inside the filament. One of the commenters mentioned they couldn't wash the fibers off their skin, and another likened it to the "3d printing equivalent of asbestos"
I don't plan to print with it just yet due to needing a hardened nozzle, and spare extruder parts. However when I do, i'm feeling a little worried about how safe it is - mainly whether the final printed part is fine for occasional skin contact, or whether this material should ideally be left to just cosmetic parts.
P.S. image not mine, taken from here
I can't find much literature about it, did find this safe handling procedures from UNSW Sydney if interested. I'd say if you're concerned, don't use it. The fibres themselves to me are a concern when out of the polymer, so take precautions when sanding or cutting, glove up and wear a mask + eye protection, probably should consider wet sanding too to reduce airborn dust. Print in an enclosure with ventilation, same precautions you'd take for abs and nylon, you don't want to be around that when it's printing. As I said though, if you do have any concerns, don't use it, there are matte finished filaments if thats the look you're going for.
What was CNC kitchen's concerns? As above, personally I'd be concerned while disturbing the plastic through printing, cutting, sanding etc, just handling it wouldn't be on the top of my list unless the plastic has degraded or been damaged in some way, pretty much how I'd treat anything with fine fibres or particles in it.
At the end of it, I'm just some guy on the internet, if you have concerns, don't risk it. If you do decide to use it, treat it with respect like you would anything with fine particles or fibres.