No, microwaves do not leak harmful radiation when they are turned off and unplugged. Microwave ovens are designed with safety features to prevent the emission of microwave radiation when not in operation. When you turn off the microwave or unplug it from the power source, it completely cuts off the power supply to the magnetron (the component that generates the microwaves), ensuring that no microwave radiation is being produced.
During regular operation, microwave ovens are designed to contain the microwave radiation within the cooking chamber. The door of the microwave is equipped with a special safety interlock system that prevents the microwave from operating if the door is not securely closed. This safety mechanism ensures that microwave radiation does not leak into the surrounding environment while the microwave is in use.
It is essential, however, to check the condition of the microwave door's seal and screen for any damages. If the door seal or screen is compromised or damaged, it could potentially lead to microwave leakage during operation. This is one reason why it's crucial to perform periodic maintenance checks and have any necessary repairs done by a qualified technician.
In summary, when a microwave is turned off and unplugged, there is no risk of harmful microwave radiation leakage. Microwave ovens are safe to use when properly maintained and operated according to the manufacturer's instructions.