The World’s Fifth-Largest Economy is About to Ban Most Polystyrene Foam [Video]

California, the most populous U.S. state and fifth-largest world economy, will effectively ban the use of most expanded plastic foam food containers on January 1, a move conservationists called a major development in the effort to limit plastic waste.

“We found that this could eliminate up to 3.9 billion pieces of foam ware every single year,” Anja Brandon, director of plastics policy at the environmental nonprofit Ocean Conservancy, told Newsweek.

Clamshell containers, cups and other food ware items made from expanded polystyrene foam are popularly—though incorrectly—called Styrofoam, which is a registered brand name for styrene foam construction materials made by DuPont. But whatever you call it, Brandon said, foam ware makes a remarkable mess when it all too often ends up as litter.