This International Standard specifies requirements and methods of testing for four categories of rigid cellular plastics thermal-insulation products for buildings. It covers rigid cellular plastics in the form of flat or profiled boards, with or without natural skins. They may also be faced or laminated with foil, plastic or metal films or sheets, mineral coatings, paper, cardboard or other materials. This International Standard is not applicable to materials used for the thermal insulation of pipes and vessels, for impact sound absorption or for acoustical insulation. This International Standard covers the following cellular materials used in the thermal insulation of buildings: PF based on phenolic polymer; EPS based on expanded polystyrene; XPS based on extruded polystyrene; PUR based on polyurethane. The limiting quality values in this International Standard are for use only in the specification of materials between purchaser and supplier, and are not intended to be used for design purposes. Additional requirements for special applications may be added to those specified in this International Standard by agreement between purchaser and supplier.