Food-grade silicone.Eco-friendly,non-toxic,flexible,reusable and. Silicone are naturally stick to make popping out perfectly shaped baked treats a. Our liners are designed to withstand thousands for time' usage,totally a money saver. Easy to clean.Microwave,oven,refrigerator,freezer and dishwasher safe. Silicone are great for baking muffins,cupcakes,and breads,preparing for treats,desserts on a baking sheet,candy making.