This Gulf standard is concerned with both the normal (N) and the self-extinguishing (SE) polystyrene insulation boards, not less than 13 mm* thick, used for sound and thermal insulation in buildings and cold stores at a maximum continuous service temperatures of 80?C. It is applicable to polystyrene boards derived mainly from polymerizing the styrene monomer which unit through chemical bonds, then form polystyrene beads which contain a blowing agent (pentane gas) to allow the beads to expand.