Before revision: Phaseout in the United States Polystyrene foam legislation in the United States As of February 2024, 11 U.S. states and one territory have passed statewide legislation to explicitly ban polystyrene foam: In 2019, Maryland was the first state to enact a ban, which went into effect on October 1, 2020.
After revision: Phaseout in the United States Polystyrene foam legislation in the United States As of March 2024, 11 U.S. states and two territories have passed statewide legislation to explicitly ban polystyrene foam: In 2019, Maryland was the first state to enact a ban, which went into effect on October 1, 2020.