Microwaving a phone is not safe and can cause significant damage, including fire, explosion, and release of toxic fumes. Microwaves are designed to heat food by emitting microwave radiation, which is absorbed by water molecules in the food, causing them to vibrate and generate heat. However, most phones contain metal components, such as the battery and circuitry, which can react negatively to the microwave's electromagnetic field.
Microwaving a phone can result in a variety of hazards, including electrical shorts, overheating, melting of plastic components, and potentially hazardous chemical reactions. There is no safe duration for microwaving a phone, as any amount of time can be detrimental.
If you have a damaged or non-functional phone that you need to dispose of, it is best to consult with a local electronics recycling facility or follow the proper procedures outlined by your local waste management authorities.