The use of local materials goes hand-in-hand with the use of natural materials. Not only does resource-productivity imply less highly-processed materials, but natural materials also tend to be less toxic. In eco-industrial production, waste equals foodin that every output is designed to be an input for some other process. If everything is food for something else, this suggests that this food must be non-toxic enough to be a nutrient for the system it feeds. And ultimate end-substances must also be able to be safely composted into the Earth itself. In Chapter III on manufacturing, and then again in Chapter IV on recycling, I will explore more specifically production in the Lake Economy, both generally and as it applies to building materials. Now however, lets look more closely at the general goals of dematerialization and detoxification.