• Greenpeace has published a report on how heating ready meals in plastic containers in the microwave or oven can release microplastics into food.
• Labels such as "oven-safe" or "microwave-safe" would be false reassurances.
• According to Greenpeace, governments should intervene with new regulations to protect human health and reduce plastic production.

Microplastics are tiny plastic particles now found everywhere in the environment. According to numerous studies, they can pose a health risk when ingested or inhaled, as they are able to enter the body and accumulate in tissues.

One of the main routes of exposure to microplastics is through food. These substances can migrate into food from the containers used to store it, such as plastic trays and bottles, but also from certain utensils used during preparation and cooking.

Heating food in plastic packaging and the risk of microplastic release: the Greenpeace study

According to the Greenpeace International report "Are We Cooked? The Hidden Health Risks of Plastic-Packaged Ready Meals", heating ready meals and takeaway food packaged in plastic containers in the microwave or oven can release hundreds of thousands of microplastic and nanoplastic particles directly into food, along with a mixture of toxic substances. The peer-reviewed analysis examined 24 recent scientific studies.

"People think it is safe to buy and heat a meal packaged in plastic: in reality, we are being exposed to a mix of microplastics and hazardous chemicals that should never come into contact with the food we eat," said Graham Forbes, head of Greenpeace USA's global plastics campaign.

One of the studies analysed by Greenpeace found that between 326,000 and 534,000 particles disperse into food simulants after just five minutes of microwave heating, up to seven times more than oven heating. Heating dramatically increases chemical contamination: in several studies, common plastic samples subjected to microwaving — such as polypropylene and polystyrene — released chemical additives into food or food simulants, including plasticisers and antioxidants.

Of the chemical substances present in plastics that come into contact with food, at least 1,396 have also been detected in the human body — a cause for concern given the growing body of evidence linking exposure to these substances with neurodevelopmental disorders, cardiovascular disease, obesity and type 2 diabetes.

Old, scratched or reused containers are the most problematic: worn plastic releases almost twice as many microplastic particles as new packaging.

Greenpeace: "New regulations are needed to protect health and reduce plastic production"

Plastic-packaged ready meals represent one of the fastest-growing segments in the global food system, with a value of nearly 190 billion dollars, according to research by Towards FnB. In 2024, the production of ready meals reached a global volume of 71 million tonnes, an average of 12.6 kg per capita.

At a global level, there is a lack of adequate guidelines and regulations on microplastics released by food packaging, and according to Greenpeace, labels such as "microwave-safe" or "oven-safe" provide consumers with false reassurance. The organisation argues that governments should intervene with new regulations to protect human health and reduce plastic production at source.