POLYSTYRENE

US usually [trademark] Styrofoam [noun] [U] - a light usually white plastic used esp. for putting around delicate objects inside containers to protect them from damage, or for putting around something to prevent it from losing heatThe computers arrived in large boxes, packed tightly in polystyrene.polystyrene cupsWhen we moved into the house, the ceiling was covered with horrible polystyrene insulation tiles.