STYROFOAM <> POLYSTYRENE

The Real STYROFOAM

STYROFOAM™ was invented in 1941, and was first used the next year in a Coast Guard life raft. Now, it's used exclusively in building insulation, to float docks  and in some molds for floral arrangements. It's sold in 50 countries, and Dow holds the trademark in 95 countries. With very few exceptions, it's colored light blue.

The real STYROFOAM™ has never been used to hold food and beverage containers, which are made out of the less insulative and moisture-resistant expanded polystyrene. And the maker of the real STYROFOAM™, Dow Chemical, would really like everybody to stop using the term.

That white stuff you use in takeaways... polystyrene

Source: The Washington Post