The term polystyrene means that the plastic is derived from styrene, a liquid hydrocarbon. When heated, monomer styrene molecules link together into long chains, creating a polymer material that's solid when it cools to room temperature. That clear, hard, brittle plastic was developed on a commercial basis in Germany in the 1930s. The material is used today for CD and DVD jewel cases and plastic forks. In 1941, Dow scientist Ray McIntyre invented extruded polystyrene foam (Styrofoam), a light, waterproof material that was first used for making life rafts. Expanded polystyrene (EPS) is another, similar foam material that has found even more uses.
Polystyrene is one of the most common forms of plastic. You see it in take-out coffee cups and egg cartons; it's the packing material used to cushion goods for shipping. Many call it Styrofoam, though that term is actually the brand name of a rigid blue insulation made by Dow Chemical Company. Polystyrene is a very versatile material, but polystyrene recycling isn't always easy.
The polystyrene industry claims a recycling rate of about 12 percent, according to the Alliance for Foam Packaging Recycling, but that includes scraps from EPS manufacturing, which are immediately reused. The fact is that it's often easier and cheaper to produce new polystyrene than it is to collect, transport and process material for recycling.
The most direct way for consumers to recycle polystyrene is to reuse it. This method doesn't work as well with coffee cups and plastic forks, but it's ideal for packaging materials. Packing peanuts can simply be collected and used again. Shippers may take rigid packaging and chop into small pieces to use as loose packing.