Shouldn't be, but I would take precaution to it though. Its liek some stuff in life is in a way not harmful to hands but precautions are needed. Like Fantastic, 409, chlorox bleach, liquid plumbr, draino, and other household chemiclals.
I wouldn't worry about it though, how bad can Klasse be? Its only protecting your hands by making water bead...LOL j/k