Leaving a microwave open without any food inside it should not pose a risk of fire or explosion. Microwave ovens are designed with safety features that prevent them from generating microwaves when the door is open.
When you open the microwave door, it activates an interlock switch that interrupts the power supply to the magnetron (the component that produces microwaves). This prevents the microwave from emitting microwaves when the door is open. As a result, even if the microwave is turned on with the door open, it should not generate microwaves or pose a risk of fire or explosion.
However, it's essential to use your microwave as intended and not try to bypass or disable any safety mechanisms. If you suspect that your microwave is malfunctioning or not operating correctly, it's best to have it inspected and repaired by a qualified technician.
While leaving the microwave open without food inside may not cause a fire or explosion, it's generally not recommended to run the microwave with the door open or leave it unattended while it's operating. This is because the microwave may produce arcing or sparking if the interior metal components are exposed, which can damage the oven and create a potential safety hazard.