American Society for Testing and Materials (ASTM) has developed the Standard Specification for Rigid Cellular Polystyrene Insulation Thermal Insulation, C578. This guide provides EPS manufacturers as well as specifiers with the types, properties, dimensions, sampling and test procedures, and ordering instruction for EPS foam insulation. The table indicates the minimal requirements for each classification. Specifiers utilize this information to accurately determine the type of EPS needed to meet the required energy codes, thus manufacturers can easily provide the appropriate product without confusion or problems.