Most EPS products are actually 90 percent or more air, because it is the only rigid foam of insulation that has never been made with CFCs, HCFCs, or hydrofluorocarbons (HFCs) (verify with the specific manufacturer). During manufacture, polystyrene beads are expanded with pentane, a hydrocarbon that contributes to smog but is not implicated in ozone depletion or global warming. The pentane quickly diffuses out of the insulation and is replaced by air during the manufacturing process. To meet federal and state clean air requirements, several EPS manufacturers have redesigned their plants to collect and control up to 95 percent of the pentane used in production. BASF Corporation also has developed a low – pentane EPS bead formulation.7
EPS products also can be made from recycled EPS. This is accomplished by crumbling the old EPS foam into small particles, mixing it with virgin prepuff, and remolding the material into usable products. Most clean EPS waste can be recycled into cushion packaging, but because of building code requirements, waste EPS construction products can only be recycled into noninsulation building applications.
EPS is inert and nontoxic. The styrene used in polystyrene insulation is identified by the EPA as a possible carcinogen, mutagen, chronic toxin, and environmental toxin. Furthermore, styrene is produced from benzene, another chemical with both environmental and health concerns.7