The Souleo dinner ware and serving pieces meet FDA and Proposition 65 requirements. The Souleo pottery is dishwasher and microwave safe. For the dishwasher use the energy save/air dry cycle. For the use in the microwave oven follow certain precautions: Use a oven mitten / pot holder/ to take dish out of the oven Do not put the dish into the microwave without food or liquid Bakeware does NOT go from the freezer directly into the oven. Bakers should be placed in a room temperature oven and then brought to cooking up to 400 degrees Fahrenheit. Jars, vases and cache pots should not be left out during the winter. Freezing water may cause cracks and breakage.