I don't know why it "Sounds toxic as s*t". It's a reactive salt. LD50 is ~1gram so don't swallow or get it in your eyes or nose. It seems comparable in hazard to commonly available cleaning compounds like ammonia and bleach.

That doesn't make it safe, but it's not a crazy carcinogen or auto-immune risk, and it literally dissolves in water. It's present in all sea water ~0.1ppm so you can't escape it.