Running a microwave empty can lead to excess microwave leakage, but it's not the main concern. Microwave ovens are designed to be safe and should not produce significant microwave leakage under normal operating conditions. When the microwave oven is working correctly and the door is intact and properly sealed, there should be minimal microwave radiation escaping the oven.
The main issue with running a microwave empty is the potential for damage to the microwave itself. Microwaves are designed to heat food or liquids, not the interior of the oven. When there is nothing to absorb the microwave energy, it can bounce around inside the oven, potentially leading to an increased risk of damaging the magnetron (the component that generates the microwaves) or other parts of the microwave.
To maintain the safety and longevity of your microwave, it's best to avoid running it empty. Always ensure there is something inside the microwave that you intend to heat or cook. This could be food, water, a microwave-safe container, or a microwave-safe object that you are specifically using for purposes like sterilization or reheating. Additionally, if you notice any issues with your microwave, such as a damaged door seal or unusual sounds during operation, it's essential to have it inspected and repaired by a qualified technician to ensure its safe and proper functioning.