What is the best Way dispose of burnt fiberglass from a motorhome fire, is it toxic?

our motor home caught fire and was totaled we did not have insurance and are try to clean up the mess our selves. hoping to scrape what metal we salvage but what do we do with the burnt fiberglass and the soot and ashes from it,its not nice to work with. I can not go out there myself because a developed a really ugly rash. my poor mate is doing it himself. how harmful is this stuff he breathing??