Amsterdam – Heating plastic-packaged ready meals and takeaways in the microwave or oven can release hundreds of thousands of micro- and nanoplastic particles along with a cocktail of toxic chemicals directly into food, according to a new Greenpeace International analysis of peer-reviewed science.
The report, Are We Cooked? The Hidden Health Risks of Plastic-Packaged Ready Meals, reviewed 24 recent scientific studies and finds that convenience food items marketed as "safe-to heat" are in fact potentially exposing millions of people to invisible contaminants every day.
Graham Forbes, Global Plastics Campaign Lead from Greenpeace USA, said:
"People think they're making a harmless choice when they buy and heat a meal packaged in plastic. In reality, we are being exposed to a cocktail of microplastics and hazardous chemicals that should never be in or near our food. Governments have let the petrochemicals and plastics industries turn our kitchens into testing labs. This report shows that corporate claims of "microwave-safe" are no more than wishful thinking. "
Key findings are:
- Microwaving plastic containers can release hundreds of thousands of micro- and nanoplastics in minutes. One study found 326,000 to 534,000 particles leaching into food simulants after just five minutes of microwave heating, up to seven times more than oven heating.
- Heating dramatically increases chemical contamination. Across multiple studies, microwave test samples of common plastics such as polypropylene and polystyrene leached chemical additives into food or food simulants, including plasticisers and antioxidants.
- More than 4,200 hazardous chemicals are known to be used in or present in plastics, most are not regulated in food packaging. Some, like bisphenols, phthalates, PFAS "forever chemicals" and even toxic metals such as antimony, are linked to cancer, infertility, hormone disruption and metabolic disease.
- Plastic chemicals are already in our bodies. At least 1,396 food contact plastic chemicals have been detected in human bodies, with growing evidence linking exposure to neurodevelopmental disorders, cardiovascular disease, obesity and type 2 diabetes.
- Old, scratched or reused containers are worse. Worn plastic releases nearly double the number of microplastic particles compared to new packaging.
Plastic-packaged ready meals are one of the fastest-growing segments of the global food system, worth nearly US$190 billion and rising sharply as households rely more on convenience food, according to a research done by Towards FnB. In 2024, production of ready meals amounted to a global volume of 71 million tonnes, averaging 12.6 kg per person, with the cost of a ready meal and revenue per capita also expected to increase, according to a market research published by Statista. International Energy Agency analysis also showed that plastic packaging accounts for about 36% of all plastics, with global plastic production set to more than double by 2050 from current levels.
Regulators have failed to keep up. There is insufficient regulatory guidance around the world on microplastics released from food packaging, and labels such as "microwave safe" or "oven safe" provide what the report calls false reassurance to consumers.
The report warns that the plastics crisis is following the same pattern seen with tobacco, asbestos and lead. While there are overwhelming scientific warning signs, it has been met with industry denial and regulatory delay.
In the U.S. alone, the social cost of plastic across its lifecycle is estimated to be up to US$1.1 trillion per year, according to a report by Duke University.
As governments negotiate the UN Global Plastics Treaty, Greenpeace is urging negotiators to act on the precautionary principle and end this uncontrolled and unregulated plastic and chemical contamination that threatens human health.
"Are we being poisoned while trying to feed our families? The risk is clear, the stakes are high and the time to act is now. We cannot rely on misleading promises from corporations. Governments must act now by delivering a strong Global Plastics Treaty that protects human health and cuts plastic production at the source," Forbes said.
