Polystyrene

Polystyrene (PS) ( /ˌpɒliˈstaɪriːn/) is an aromatic polymer made from the monomer styrene, a liquid petrochemical. Polystyrene is one of the most widely used plastics, the scale of its production being several billion kilograms per year. It is a colorless solid that is used, for example, in disposable cutlery, plastic models, CD and DVD cases, and smoke detector housings. Products made from foamed polystyrene are ubiquitous, for example packing materials, insulation, and foam drink cups. Its very slow biodegradation is a focus of controversy, and it is often abundant as a form of litter in the outdoor environment, particularly along shores and waterways especially in its low density cellular form.