Made from plant based PLA (polylactic) compostable plastic. Great for cold foods such as green salads, pasta salads, and desserts from deli counters, takeout restaurants, grocery stores and cafes. Freezer safe. 100% compostable in two to four months in a commercial composting facility. Not microwavable. PLA products should be stored in a cool place below 110°F and out of direct sunlight. Matching PLA lids are available separately.