Two areas of concern have been raised about microwave ovens over the years. The first is whether they produce harmful radiolytic compounds in food. The type of radiation used in microwave ovens is not the ionising radiation (such as X-rays and gamma rays) that cause molecular bonds to break and create radiolytic compounds. Microwave radiation doesn't break molecular bonds, it stretches them.
The second area of concern is the possibility of radiation leakage from the unit. Owners can maintain low leakage by keeping their unit in good working order and not abusing it. This means not allowing dirt to accumulate around the door seals, not damaging the door or door seals, and always replacing or repairing worn-out door hinges and latches.