Also available as a pack of 50, SKU - CPL-CS-12SH-P. World Centric compostable 9 to 24 ounce cold cup portion lids are made from PLA, (polymer made from plants). They are suitable for cold liquids, and freezer safe. Not microwavable. PLA products should be stored in a cool place below 110 deg F and out of direct sunlight. These are certified compostable in a commercial facility, which may not exist in your area.