These World Centric® compostable 4 ounce clear portion cups are made from PLA, which is derived from plants. They are suitable for cold liquids, freezer safe and compost in 2 to 4 months in a commercial composting facility. Even though they are as light and strong as plastic, these disposable portion cups fully break down when commercially composted. These portion cups work well for condiments, sides, dips, dressings, or toppings. Not microwavable. PLA products should be stored in a cool place below 110° F and out of direct sunlight.