Most dishes are safe for microwave use. However, to be sure, inspect the container in question for words that read “Microwave Safe” or for a symbol with wavy lines. These both indicate that a dish is microwave safe. If your dish or container doesn’t have any of this, you can still test if it’s safe for use in microwave ovens. Fill a microwave-safe cup with water and place it in the microwave next to the dish you want to test. Run the microwave on its highest power level for one minute. If the dish in question is hot, then it is not microwave-safe.