What is toxic mold? Strictly speaking there is no toxic mold. The correct term is "Toxigenic Mold". Toxigenic molds refer to those molds that produce byproducts toxic to humans and animals. These byproducts (secondary metabolites) are referred to as mycotoxins. Not every mold is toxigenic. It is good to know toxigenic molds do not produce mycotoxins all the time. However, since it is difficult to tell when mycotoxins are produced (unless a test is performed) food or feed contaminated with mold should never be consumed.