World Centric® compostable 9-24oz cold cup portion lids are made from PLA, (polymer made from plants). Great for holding granola or other toppings for parfaits or frozen treats. They are a sustainable alternative to plastic, suitable for cold items, and freezer safe. Not microwavable. PLA products should be stored in a cool place below 110° F and out of direct sunlight. These are certified compostable in a commercial facility, which may not exist in your area.