In my area 1/2″ OSB is the pre-dominate sheathing choice for exterior walls. In the past I have used structural fiberboard sheathing. With the increase in OSB pricing this sheathing is looking more attractive. I know it performs from a structural stand point because I have built many homes with it and never had issue. I stopped using it because it takes more supervsion to make sure the framer is installing it correctly and when it was more expensive than OSB many suppliers stopped carrying it. I have looked at specifications from a variety of manufacturers and they all claim high in recycled content, no urea formaldyhyde, and a slighter better insulation value than OSB. The product is impregnated with asphalt to help with water resistance. Does the asphalt impregnation make this product anymore toxic than OSB or other commonly used building products in a home? I have considered insulated sheathing such as the Dow product but find it hard to get from my suppliers plus it requires metal bracing or OSB on the corners.