1. Generally, porcelain plates can't be put into the oven for the following reasons: the main raw material of porcelain is kaolin, and the high-quality kaolin is non-toxic and the microwave dielectric loss is small. Ceramics made of this kaolin can be put into an oven without toxicity. However, some ceramics made of kaolin mixed with metal impurities are not suitable for microwave containers. If put in the microwave oven, it may be toxic and cannot be used.

2. If the colored glaze on the ceramics is inferior, putting such ceramics in the oven will also cause toxic spillover.

3. Frozen ceramics should not be put into microwave oven immediately. Experienced people all know that if you put the ceramics and pottery just taken out of the refrigerator into the microwave oven at once, they are likely to burst.

4. Ceramic bowls with metal edges are not suitable for microwave ovens. Metal products can't be put in the microwave oven, so if there are metal edges or metal patterns on the ceramic bowl, don't put it in the microwave oven.