San Diego announced that its ban on many polystyrene foam products would take effect April 1, moving the policy from adoption into enforcement.
Affected businesses had to replace common foam food-service containers and other covered products with permitted alternatives. The city paired the deadline with information about the rule and available exemptions.
The ban targeted material that readily becomes litter and is difficult to recycle. Its environmental result would depend on compliance and on the life-cycle impacts of the substitutes businesses chose.