Microwave and freezer safe, and can be used for both hot and cold items soak proof. Product has no plastic or wax lining. Handles hot liquids up to 220° F (moisture forms at the bottom for hot food items). Fully compostable, sturdy and strong. Meet ASTM D-6400 standard for compostability. Though these compostable souffles are soak proof, hot items will cause the plates to "perspire" and some condensation will form at the bottom.