[Material] Polystyrene–Extruded (XPS) Foam Insulation [Pros] * More moisture resistant than EPS * Typically no indoor air quality effects * Recyclable [Cons] * Most products still use HCFCs (but they are to be phased out by 2010) * Made from petrochemicals * Contains highly toxic HBCD brominated flame retardant and other toxins [Application Tips] 
Foam insulation boards. Appropriate for larger projects or new construction in areas with moderate to no moisture. Best for interior basement walls, beneath siding, attic ceilings or below grade.