No need to be afraid of extra toxins in an ICF home. This foam block is odorless and there is no off gassing. The foam has been given a food clearance. What about if there is a fire? Is the smoke toxic if a fire should occur? Byproducts of the combustion are CO2, CO and H2O, which suffocates, but the concentration of CO is considerably less than that given off during the combustion of an equal volume of wood and other commonly used building materials. ICF is not nearly as toxic as burning carpet or a sofa.