Is it safe to use plastic containers in microwave oven? Healthy ways to use it

My mother found joy in cooking and serving delicious food to her loved ones. However, her life was confined to the four kitchen walls blackened by the smoke from the traditional woodfire stove. I, too, have inherited her love and skills for cooking, but unlike her, I am not ready to spend more than an hour in the kitchen. Cutting vegetables into perfect pieces, listening to my most loved playlist, is my favourite hobby. Not just songs, but modern kitchen appliances like air fryer, microwave oven, instant pot and dishwasher too make my cooking easier and hassle-free. 

The microwave oven was discovered by accident by an American engineer named Percy Spencer while working on radar technology using microwaves during the Second World War. Spencer was standing near an active radar set when he noticed that a chocolate bar in his pocket had melted. Instead of dismissing it, he got curious and tried it on corn, too. He quickly understood that the microwave rays must have done the ‘magic’.

The first microwave oven was called the ‘radarange’. Meanwhile, the first microwave oven that could be used in the kitchen reached the market in 1967. A microwave oven has a device called the cavity magnetron that can turn electricity into microwaves. Besides wave guides that regulate the transmission of waves, a fan, light, and a coating that prevents the rays from escaping are also part of the microwave oven. Usually, while cooking on regular stoves, the food gets cooked when the utensil is heated. However, in microwave oven, a phenomenon called dry electric heating is what does the cooking.

Here's how water is boiled in a microwave oven. Water is a polar molecule with unequal distribution of electric charges. The molecules in water begin to spin when the microwave rays hit them. The water gets boiled due to this continuous spinning. Meanwhile, plastic, ceramic and glass are made with molecules with no charge at all. So, utensils made using these could be used in microwave oven as they would not get heated much. Not just water, fat, protein and sugar too can assimilate microwave rays on small amount and get heated. 

Microwave cooking and health problems
No research has categorically proved that cooking in a microwave oven may cause health problems, including cancer. The spinning of the molecules is what causes the food items to get cooked. This phenomenon doesn’t cause any chemical changes in the food that is harmful for the human body. However, the containers that are used in microwave oven could lead to such changes. 

Microplastic and dementia
A study published in the Environmental Science and Technology journal in 2023 revealed that plastic utensils used in microwave ovens release 4 million microplastics per square centimetre into food. Meanwhile, another study that appeared in the Nature Medicine journal in February last year says that the brain of a dementia patient has ten times more microplastic than a person with no disease. But, you cannot assume that these microplastic in their brain has caused dementia. 

Microplastics and the bisphenol A (bpa) and phthalates that are formed when plastic breaks down are generally considered harmful for health. So, it is better to avoid plastic vessels and use glass or ceramic utensils in microwave oven.
(The author is the Associate Director at the Health and Bio-Medical Centre and Head of the Nanotechnology & Bio-Engineering Research Group, Atlantic Technological University (ATU Sligo), Ireland.)