Biodegradable and compostable souffle cups are made from NatureWorks polylactic acid (PLA), which is derived form plants grown in the USA. Product meets the most stringent requirements for biodegradability and compostability, and are ASTM D6400-99 certified for "compostable plastics." Product is as light and strong as plastic, but fully biodegradable when composted. Recommended for use with foods and beverages below 110°F and away from heat, hot surfaces and direct sunlight.