World Centric®; compostable clear domed lids for 12-32oz takeout paper bowls are made from PLA, (polymer made from plants) . Great for warm or cold items, these lids are heat resistant up to 110°F. 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.