There have probably been times when you melt a plate or bowl in your microwave only to find out that you had accidentally used something that did not microwave safely. Microwave-safe dishes and bowls will have a sign on the bottom that identifies them as safe for use in standard microwaves. These products will not melt and potentially ruin or damage the spinning component of the microwave dish with melted plastic.
Also, using dishes that don’t microwave-safe can add chemicals from the plastic into your food. Most microwaves safe plates and bowls are made of glass, ceramic, or heartier plastic material. Make sure to never put any metal in your microwave (even tin-foil!) as the metal will cause sparking, burning, and even shortening your circuit board within the machine.