> (NB: I do not know if or claim that basalt fibers are more dangerous than alternatives.)
For what it's worth, the ex-composite-shop guys I used to work with said that basically everything you can make a composite out of is horribly nasty: carbon fiber, fiberglass, basalt fiber, probably anything period. After repeated exposure you develop contact dermatitis to that type of fiber and the shop moves you on to working with something else, until it happens again. Contact dermatitis is just the first visible sign, it gets worse from there. Eventually you're probably going to want to get out of the shop entirely.
For what it's worth, the ex-composite-shop guys I used to work with said that basically everything you can make a composite out of is horribly nasty: carbon fiber, fiberglass, basalt fiber, probably anything period. After repeated exposure you develop contact dermatitis to that type of fiber and the shop moves you on to working with something else, until it happens again. Contact dermatitis is just the first visible sign, it gets worse from there. Eventually you're probably going to want to get out of the shop entirely.