E.P.S. (Expandable Poly Styrene) is a lightweight, rigid,plastic foam insulation material produced from solid particles ofpolystyrene. Expansion is achieved by virtue of small amounts ofpentane gas dissolved into the polystyrene base material duringproduction. The gas expands under the action of heat, applied assteam, to form perfectly closed cells of EPS. These cells occupyapproximately 40 times the volume of the original polystyrene bead.The EPS beads are then molded into appropriate forms suited totheir application. Products made from foamed polystyrene are nearlyubiquitous, for example packing materials, insulation, and foamdrink cups.