Expanded Polystyrene
foam plastics - porous or cellular plastics, whose density is artificially reduced due to a large number of small hollow spaces (pores or cells), connected to each other or having a closed structure and distributed throughout the material's volume. Foam plastics include: expanded polystyrene (expanded polyethylene foam), extruded polystyrene, and molded foam polyurethane
Source: "GOST R 53786-2010. Facade Thermal Insulation Composite Systems with External Plaster Layers. Terms and Definitions"
(approved by the Order of Rostekhregulirovaniya dated April 19, 2010 No. 61-st)