I've used 1000 grit sandpaper on my legs before. Didn't scratch or anything. In fact I only tried once, because I found that it didn't really do any exfoliating. The friend who convinced me to try it uses 600 (or 800, can't remember), on her legs regularly as a method of hair removel and keeping her legs soft. She's been doing it for about 10 years now and has never had any problems with it. I don't see why anyone would want to use it on their face, though.