The maximum temperature is 420 degree F. and longest baking time is 20 minutes. These muffin cups are made of premium quality Material that make these strong and sturdy. Put them into the oven and bake them directly. Can't be used in microwave as metal material easy to catch fire. No smells, no poison, no leaking dyes. These papers materials are all made of the best and safest material. Best choice to enhance your Birthday, Wedding, Holiday Party, themed celebrations with standard cupcake liner.