ISO 4898:2018 specifies requirements and methods of testing for three 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 can also be faced or laminated with foil, plastic or metal films or sheets, mineral coatings, paper, cardboard or other materials.

ISO 4898:2018 is not applicable to materials used for the thermal insulation of pipes and vessels, for impact sound absorption or for acoustical insulation.

ISO 4898:2018 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 document 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 can be added to those specified in this document by agreement between purchaser and supplier.