“Styrofoam” is actually just a brand name! The white material commonly used in coffee cups and as packing is actually called expanded polystyrene. Polystyrene is a type of plastic. It’s filled with 95% air which makes it a significant problem when it enters the oceans as it floats down waterways and can be ingested by wildlife. It also releases methane gases that have over 20 times the ozone destroying potency as CO2 when it sits in landfill! San Francisco and New York have both banned styrofoam.