Microwaves are indeed primarily made of metal and plastic, which are generally non-flammable materials. The internal components of a microwave, such as the magnetron and the electrical wiring, are designed to handle the high temperatures generated during normal operation without catching fire.
However, it's important to note that while the microwave itself may not be flammable, placing flammable materials on top of or near a microwave can still pose a fire hazard. If a flammable material, such as paper, cloth, or certain types of plastics, comes into contact with the hot surfaces of the microwave or its venting system, it can potentially catch fire. This is especially true if the material is exposed to high temperatures for an extended period.
Additionally, a short circuit or electrical malfunction within the microwave can potentially cause sparks or generate excessive heat, which can ignite nearby flammable materials. While such occurrences are relatively rare, it's always crucial to exercise caution and follow safety guidelines when using any electrical appliance, including microwaves.
To ensure safety, it's recommended to keep the area around the microwave clear of flammable materials and to follow the manufacturer's instructions regarding proper usage and maintenance. If a malfunction or fire does occur, it's advisable to turn off the microwave and disconnect it from the power source, if safe to do so, and contact emergency services if necessary.