Microwaving a cup with a metal handle can be potentially hazardous, but the fact that nothing happened in your situation could be due to a few reasons:
Design and materials: Some metal objects, like certain metal handles or trims, may have a design that doesn't cause significant issues when exposed to microwave radiation. Manufacturers may use metal with low microwave-absorption properties in these components to minimize the risk of sparking or damage.
Microwave-safe design: Some microwave-safe products, including certain ceramic or glass cups with metal accents, are specifically designed to be used safely in microwave ovens. These products are made with materials that are less likely to cause arcing or sparks.
Microwave's safety features: Modern microwave ovens are equipped with safety features like interlock switches, which prevent the microwave from operating when the door is open. If the microwave detected any issues due to the metal handle, it may have automatically shut off to prevent any potential hazards.
However, it's essential to remember that microwaving metal objects can be dangerous, and you should generally avoid doing so. When metal objects are placed in a microwave, they can act as antennas for the microwave radiation, causing electrical arcing (sparks) and potentially damaging the microwave or the metal object itself. Additionally, sparks from metal objects could cause a fire or damage the microwave's interior.
For safety reasons, always follow these guidelines when using a microwave:
Avoid using metal: Do not put any metal objects or containers with metal parts in the microwave. This includes aluminum foil, metal utensils, and dishes with metallic decorations.
Use microwave-safe containers: Only use containers that are labeled as microwave-safe to avoid potential risks.
Inspect containers: Before microwaving anything, check the container for any metal parts, including handles or trim.
Be cautious with foil: Avoid wrapping food in aluminum foil when microwaving, as it can cause arcing and potentially start a fire.
In your case, if nothing seemed to happen when you microwaved the cup with the metal handle, you were likely fortunate that the cup's design and materials, along with the microwave's safety features, prevented any harmful incidents. However, it's still best to avoid microwaving any objects with metal components to ensure safety.