Light, buoyant and cheap, polystyrene foam is commonly used for docks, buoys, pontoons at marinas and other water activities throughout Canada. But the plastic, oil-based product is causing a wave of pollution in oceans and waters across the country, says B.C. NDP MP Rachel Blaney. The federal government needs to ban the use of expanded polystyrene (ESP) and extruded polystyrene (XP), commonly known as Styrofoam, in floating structures in both freshwater and saltwater, said Blaney, the MP for North Island-Powell River.