How often do you eat takeaway food? What about pre-prepared ready meals? Or maybe just microwaving some leftovers you had in the fridge? In any of these cases, there’s a pretty good chance the container was made out of plastic. Considering that they can be an extremely affordable option, are there any potential downsides we need to be aware of? We decided to investigate.
Scientific research increasingly shows that heating food in plastic packaging can release microplastics and plastic chemicals into the food we eat. A new Greenpeace International review of peer-reviewed studies finds that microwaving plastic food containers significantly increases this release, raising concerns about long-term human health impacts. This article summarises what the science says, what remains uncertain, and what needs to change.
There’s no shortage of research showing how microplastics and nanoplastics have made their way throughout the environment, from snowy mountaintops and Arctic ice, into the beetles, slugs, snails and earthworms at the bottom of the food chain. It’s a similar story with humans, with microplastics found in blood, placenta, lungs, liver and plenty of other places. On top of this, there’s some 16,000 chemicals known to be either present or used in plastic, with a bit over a quarter of those chemicals already identified as being of concern. And there are already just under 1,400 chemicals that have been found in people.
Not just food packaging, but plenty of household items either contain or are made from plastic, meaning they potentially could be a source of exposure as well. So if microplastics and chemicals are everywhere (including inside us), how are they getting there? Should we be concerned that a lot of our food is packaged in plastic?
Greenpeace analysis of 24 articles in peer-reviewed scientific journals found that the plastics we use to package our food are directly risking our health.
Heating food in plastic packaging dramatically increases the levels of microplastics and chemicals that leach into our food.
Plastic food packaging: the good, the bad, and the ugly
The growing trend towards ready meals, online shopping and restaurant delivery, and away from home-prepared meals and individual grocery shopping, is happening in every region of the world. Since the first microwaveable TV dinners were introduced in the US in the 1950s to sell off excess stock of turkey meat after Thanksgiving holidays, pre-packaged ready meals have grown hugely in sales. The global market is worth $190bn in 2025, and is expected to reach a total volume of 71.5 million tonnes by 2030. It’s also predicted that the top five global markets for convenience food (China, USA, Japan, Mexico and Russia) will remain relatively unchanged up to 2030, with the most revenue in 2019 generated by the North America region.
A new report from Greenpeace International set out to analyse articles in peer-reviewed, scientific journals to look at what exactly the research has to say about plastic food packaging and food contact plastics.
Here’s what we found.
Our review of 24 recent articles highlights a consistent picture that regulators, businesses and
consumers should be concerned about: when food is packaged in plastic and then microwaved, this significantly increases the risk of both microplastic and chemical release, and that these microplastics and chemicals will leach into the food inside the packaging.
And not just some, but a lot of microplastics and chemicals.
When polystyrene and polypropylene containers filled with water were microwaved after being stored in the fridge or freezer, one study found they released anywhere between 100,000-260,000 microplastic particles, and another found that five minutes of microwave heating could release between 326,000-534,000 particles into food.
Similarly there are a wide range of chemicals that can be and are released when plastic is heated. Across different plastic types, there are estimated to be around 16,000 different chemicals that can either be used or present in plastics, and of these around 4,200 are identified as being hazardous, whilst many others lack any form of identification (hazardous or otherwise) at all.
The research also showed that 1,396 food contact plastic chemicals have been found in humans, several of which are known to be hazardous to human health. At the same time, there are many chemicals for which no research into the long-term effects on human health exists.
Ultimately, we are left with evidence pointing towards increased release of microplastics and plastic chemicals into food from heating, the regular migration of microplastics and chemicals into food, and concerns around what long-term impacts these substances have on human health, which range from uncertain to identified harm.
The known unknowns of plastic chemicals and microplastics
The problem here (aside from the fact that plastic chemicals are routinely migrating into our food), is that often we don’t have any clear research or information on what long-term impacts these chemicals have on human health. This is true of both the chemicals deliberately used in plastic production (some of which are absolutely toxic, like antimony which is used to make PET plastic), as well as in what’s called non-intentionally added substances (NIAS).
NIAS refers to chemicals which have been found in plastic, and typically originate as impurities, reaction by-products, or can even form later when meals are heated. One study found that a UV stabiliser plastic additive reacted with potato starch when microwaved to create a previously unknown chemical compound.
We’ve been here before: lessons from tobacco, asbestos and lead
Although none of this sounds particularly great, this is not without precedence. Between what we do and don’t know, waiting for perfect evidence is costly both economically and in terms of human health. With tobacco, asbestos, and lead, a similar story to what we’re seeing now has played out before. After initial evidence suggesting problems and toxicity, lobbyists from these industries pushed back to sow doubt about the scientific validity of the findings, delaying meaningful action. And all the while, between 1950-2000, tobacco alone led to the deaths of around 60 million people. Whilst distinguishing between correlation and causation, and finding proper evidence is certainly important, it’s also important to take preventative action early, rather than wait for more people to be hurt in order to definitively prove the point.
Where to from here?
This is where adopting the precautionary principle comes in. This means shifting the burden of proof away from consumers and everyone else to prove that a product is definitely harmful (e.g. it’s definitely this particular plastic that caused this particular problem), and onto the manufacturer to prove that their product is definitely safe. This is not a new idea, and plenty of examples of this exist already, such as the EU’s REACH regulation, which is centred around the idea of “no data, no market” – manufacturers are obligated to provide data demonstrating the safety of their product in order to be sold.
Greenpeace analysis of 24 articles in peer-reviewed scientific journals found that the plastics we use to package our food are directly risking our health.
Heating food in plastic packaging dramatically increases the levels of microplastics and chemicals that leach into our food.
But as it stands currently, the precautionary principle isn’t applied to plastics. For REACH in particular, plastics are assessed on a risk-based approach, which means that, as the plastic industry itself has pointed out, something can be identified as being extremely hazardous, but is still allowed to be used in production if the leached chemical stays below “safe” levels, despite that for some chemicals a “safe” low dose is either undefined, unknown, or doesn’t exist.
A better path forward
Governments aren’t acting fast enough to reduce our exposure and protect our health. There’s no shortage of things we can do to improve this situation. The most critical one is to make and consume less plastic. This is a global problem that requires a strong Global Plastics Treaty that reduces global plastic production by at least 75% by 2040 and eliminates harmful plastics and chemicals. And it’s time that corporations take this growing threat to their customers’ health seriously, starting with their food packaging and food contact products. Here are a number of specific actions policymakers and companies can take, and helpful hints for consumers.
Policymakers & companies
- Implement the precautionary principle:
- For policymakers – Stop the use of hazardous plastics and chemicals, on the basis of their intrinsic risk, rather than an assessment of “safe” levels of exposure.
- For companies – Commit to ensure that there is a “zero release” of microplastics and hazardous chemicals from packaging into food, alongside an Action Plan with milestones to achieve this by 2035
- Stop giving false assurances to consumers about “microwave safe” containers
- Stop the use of single-use and plastic packaging, and implement policies and incentives to foster the uptake of reuse systems and non-toxic packaging alternatives.
Consumers
- Encourage your local supermarkets and shops to shift away from plastic where possible
- Avoid using plastic containers when heating/reheating food
- Use non-plastic refill containers
Trying to dodge plastic can be exhausting. If you’re feeling overwhelmed, you’re not alone. We can only do so much in this broken plastic-obsessed system. Plastic producers and polluters need to be held accountable, and governments need to act faster to protect the health of people and the planet. We urgently need global governments to accelerate a justice-centred transition to a healthier, reuse-based, zero-waste future. Ensure your government doesn’t waste this once-in-a-generation opportunity to end the age of plastic.
In the thick of the COP29 climate summit in Azerbaijan in 2024, the UN climate talks were rattled by what can only be described as a major PR disaster. The BBC, Reuters and The Guardian all carried headlines, attributed to leading climate policy experts, that the COPs were “no longer fit for purpose”.
The articles outlined a series of reforms called for in an open letter signed by 22 eminent scientists and politicians, including a former UN secretary-general and previous UN climate chief, with a further 150 lending their support. The headlines shook confidence in the COP process, just as governments were wrestling over a new climate finance goal.
The Club of Rome – which handled the media relations for the letter – hurried to say that its “constructive, supportive ideas” had been “misinterpreted”. Negotiators kept calm(ish) and carried on, in the end landing the finance goal after some high-stakes drama on the final day.
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To my surprise, when I went back this week to read the letter again, I could not find the offending line about the COPs not being fit for purpose. The Club of Rome has yet to respond to my query about its disappearance.
Whatever happened to the wording, that sentiment has been widely shared. COPs have ballooned in size while the importance of their outcomes seems to have diminished since the 2015 Paris Agreement (with the exception of the 2023 COP in Dubai where countries agreed to transition away from fossil fuels in energy systems).
The same on the surface
Two years on from those painful headlines in Baku, has anything changed for the better? You might be forgiven for thinking not. Official decisions are still made by consensus rather than the majority voting some have called for to stop blockers.
Tens of thousands of officials, activists and business execs still scurry around the halls to an ever-growing list of side events, roundtables and dialogues, while deals still come down to rows, all-nighters and jargon-filled texts adopted to rounds of applause.
But it would not be true to say that COPs have completely failed to respond to the very real need to translate the words of the Paris Agreement into action in the outside world.
Global warming is projected to be around 1.3C lower this century than it would have been if the world had not committed to tackle the climate crisis under that accord. Developing countries have a valued space at COPs in which their voices have equal weight in decision-making, unlike in many other international fora. And most importantly, perhaps, there has been a subtle shift, tipping the balance away from negotiating towards doing.
Brazil branded last year’s summit in Belém as the “COP of Implementation”, corralling the sprawling Action Agenda into six axes. This was a bid to impose some structure on the mushrooming efforts between governments, UN agencies, cities, businesses and civil society to set targets and spur faster results on their pet issues, from methane emissions to health and adaptation in conflict zones. COP30 alone saw the launch of 120 “plans to accelerate solutions”.
COP30 roadmaps off the cuff
Meanwhile, as the formal negotiations drew to a close, it was clear that consensus decision-making was evolving into something a little more improvised.
With only around half of all countries on board with the idea of a roadmap to transition away from fossil fuels, COP30 President André Corrêa do Lago announced his team would put one together over the coming year, along with another on how to meet a global goal to halt deforestation by 2030. Those roadmaps will be launched next week, presented and discussed at COP31, though it’s still unclear whether or how they’ll be incorporated into the formal negotiating agenda.
Some leading policy-makers don’t think that matters too much. Speaking to journalists before the Antalya summit, COP30 CEO Ana Toni and Dutch climate minister Stientje van Veldhoven said “coalitions of the willing” can move ahead without needing consensus from the COPs. This, they said, was evident this year at the first global conference on TAFF, co-chaired by van Veldhoven and attended by 60 countries.
“Consensus or no-consensus in the general COP doesn’t make a difference for the choices I have to make in my country to get my country to phase out fossil fuels,” said the Dutch minister. The Netherlands recently became one of the first to publish a national TAFF plan.
COP31 banks on flagship voluntary initiatives
This thinking has permeated the management and expected outcomes of this year’s COP too. Earlier this year, Türkiye, supported by international energy agencies, floated the idea of a voluntary goal to boost electrification to 35% of the world’s final energy consumption by 2035 – and this is now being touted as one of the main results to be expected from Antalya.
Türkiye is also championing a pledge on AI and climate, while co-host Australia is pushing to ease access to climate finance for least developed countries and small island states.
COP31 presidency announces AI pledge as UN climate chief says Big Tech ‘on thin ice’
None of these needs consensus. But with a political cover decision already in the works, as trailed by the COP presidents, they – and perhaps the fossil fuel roadmap – may find a home in the official text if language acceptable to most can be found, giving them them additional weight.
UNFCCC reform process in the shadows
Formal reform is underway too, if quietly. UN climate chief Simon Stiell is leading a review informed by ongoing consultations with a group of 15 well-respected climate policy experts, three of whom signed the open letter in 2024.
Among them is leading Swedish climate and sustainability scientist Johan Rockström who has strong ideas about how to make COPs function better, including a switch to majority voting. He told the same press briefing nothing stands in the way of this, because the rules of procedure for making decisions at COPs have never been formally agreed.
Still, to get away from the default setting of consensus would require agreement on a new system that may be impossible to achieve given the rise in bullying tactics by fossil fuel heavyweights.
Comment: The UN climate process was built for negotiation – now it must support implementation
The deliberations with the high-level policy gurus, as reflected in a summary of June’s session in Bonn, largely echo what’s already happening organically, calling for stronger partnerships and accountability both in and between the Action Agenda and negotiations. It doesn’t mention voting.
A general overview of the reform exercise says that “improving and optimizing the [UN climate] process over the medium to long term… will be critical to fostering trust, enhancing collaboration, and catalyzing increased ambition”.
In the short term, don’t hold your breath for anything concrete on reform at COP31 but watch for signs in what ends up dominating the headlines from Türkiye.
The post Editor’s Desk: COP reform is happening quietly, behind the headlines appeared first on Climate Home News.
Editor’s Desk: COP reform is happening quietly, behind the headlines
With the COP31 climate summit in Turkey looming, all eyes are on China to see what the country will push for in the negotiations.
At COP30 last year, China helped to secure a “dialogue” on climate-related “unilateral trade measures”, as well as a two-year “work programme” concerning climate finance.
The nation also championed south-south cooperation throughout the conference and co-led a summit on methane, alongside Brazil and the UK.
In a recent press conference, China’s environment vice-minister Li Gao noted the need to “uphold multilateralism” and send a “clear political signal” that the global community is united around climate action.