Made from plant based NatureWorks Ingeo™ PLA compostable plastic. Manufacturing PLA produces 75% fewer greenhouse gases and uses 50% less non-renewable energy compared to conventional plastics made from petroleum. Great for all cold beverages such as iced coffee, iced tea, smoothies, and water, but can also hold liquids up to 120°F. Freezer safe. Even though they are as light and strong as plastic, these disposable cups fully break down and are 100% compostable in two to four months in a commercial composting facility. Not microwavable.