Processed meats can form harmful compounds when microwaved. They also cook unevenly, making them unsafe to eat.
Leafy greens can release high levels of nitrates when heated in a microwave. These nitrates may become toxic during cooking.
Grapes should never be microwaved. They can produce sparks or even catch fire due to their sugar and water structure.
Unpierced potatoes can explode from trapped steam. If you must microwave them, always poke holes first.
Some cheeses melt unevenly and may burn or smoke in the microwave. They can also turn rubbery instead of soft.