Benchmark Foam
About EPS

Expanded polystyrene (EPS) is a rigid closed cell/cellular plastic resin made from petrochemicals derived from crude oil. The resin is incorporated with the blowing agent pentane. During the pre-expansion, steam softens the plastic resin causing the pentane to expand the plastic into beads at least 100 times their original size.

As long as the plastic is exposed to steam, the longer the pentane expands, therefore determining the expanded size of the bead. Before all of the pentane is displaced by air, the pre-expanded bead is then placed into a mold of any shape or block. Blocks are then cut to desired size with hot wires, wrapped, and shipped.

Benchmark Foam’s EPS products are used in building envelope applications essential to achieving energy savings in new construction and building renovations.

Other EPS Facts:

  • EPS does NOT contain CFC’s, HCFC’s, or formaldehyde.
  • EPS does NOT contribute to the growth of mold or mildew.
  • EPS is considered to be no more toxic than Douglas Fir wood under the worst case fire scenario.
  • EPS is manufactured in accordance with ASTM C578.
  • EPS is recyclable.   


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