• We often microwave foods in plastic containers and wrapping and this comes wit a risk: the risk of ingesting phthalates. When exposed to heat, these plastic additives can break down and leach into food.
• Phthalates are common (in toys and body lotions for example) and it’s still unclear just how much damage they do. But most experts agree that heating plastic with phthalates can increase exposure.
• The best way to avoid this is to use other microwave-safe materials than plastic, such as ceramic. If you do use plastic containers, avoid any that are losing their shape, since old and damaged containers are more likely to leach chemicals.

• Even if you avoid plastics, there are other potential risks of heating food in the microwave – including uneven heating, and the high temperatures used.
• Consider using microwaves to reheat, rather than cook, food, as it may cook unevenly.
• Reheating food comes with risks, too. Food must be heated until it is 82C (176F) throughout to kill any harmful bacteria, and because bacteria can still grow each time food cools back down, you shouldn’t reheat a meal more than once.

Microwaves use low frequency electromagnetic radiation (same as in lightbulbs and radios).

When you put food inside a microwave, it absorbs these microwaves, which makes water molecules in the food vibrate, causing friction that heats up the food. Humans absorb electromagnetic waves, too. But microwave ovens produce relatively low frequency waves and they are contained inside the microwave.