World Centric compostable 8x6" clear lids are made from NatureWorks Ingeo™, which is derived from plants grown in the U.S. These disposable lids are great for hot or cold food items in takeout restaurants or cafes. Even though they are as light and strong as plastic, they fully break down when composted. Composts in 2 to 4 months in a commercial composting facility. Not microwave or oven safe.