All About Plastics: Polystyrene facts

What is PS?

Polystyrene is a lightweight polymer that comes in two types; high-impact polystyrene (HIPS) and expandable polystyrene (PS-E or EPS). It was first sold commercially in the 1930s as an economic plastic to enhance food hygiene and extend product shelf-lives. PS is commonly used in the food and beverage industry as takeaway containers, vegetable punnets, disposable cutlery and plastic cups. PS is also recycled into lightweight cement blocks for the building industry.

Its lightweight nature makes PS an energy-efficient plastic to produce with a low carbon footprint. This plastic is in high demand by recyclers as it is used to manufacture seedling trays, combs, rulers, picture frames and clothing hangers. It is the sixth-most processed polymer by South African recycling facilities. Due to the well-established waste collection network and the fact that plastic food and drink containers form a large portion of our waste, 5572 tonnes of lightweight polystyrene packaging were recycled in 2018 alone.

Benefits of PS packaging

PS has numerous unique characteristics that make it a valuable packaging material. The two types of polystyrene have different applications. HIPS is a transparent and semi-flexible plastic that is used to make fruit and vegetable containers (like grape punnets) as well as CD cases. PS-E is a foam-like polymer that is used to make vending cups, meat trays (like boerewors punnets) and cooler boxes.

PS is heat-resistant and acts as a good insulator – hence its widespread use in the food and beverage sectors. It is fairly easy to recycle and can even improve the aeration in landfills if it is not sent to a recycling facility. The furniture and domestic housewares markets are the two largest consumers of PS recyclate.

PS is non-toxic and non-reactive, so it can be used in food and beverage contact applications without affecting the consumer. These characteristics and benefits make PS a highly-valuable plastic packaging material in South Africa.