Plastics in our food: biting off more than we can chew?

A new study has found that our bodies absorb 25% of food-contact chemicals found in packaging. Should we be worried?

Tad Kirakowski: Public is ‘sick of plastics’, and wants change . Picture: Brian Lougheed

Breakfast cereal is packed in plastic. So are lunchtime sandwiches, takeaway dinners, and soft drinks. Even fresh fish, meat, fruits, and vegetables come wrapped in a thin film of it.

Plastic is the airtight material of choice for packaging food.

Cheap, flexible, and lightweight, it keeps food safe and clean and allows it to be transported around the world. It also extends food’s shelf life, which is then reflected in lower supermarket prices.

However, there are reasons to be concerned about its use in food packaging.

“Plastic was supposed to be inert,” says Dr Jacob de Boer, a professor in environmental chemistry and toxicology at the Vrije University of Amsterdam and editor-in-chief of the scientific journal Chemosphere.

“But some chemicals have been shown to leach from plastic into food.”

A new study by the Swiss-based Food Contact Chemicals and Human Health Project has highlighted further cause for concern: Our bodies absorb 25% of the food-contact chemicals (FCCs), found in plastic packaging, plastic food processing equipment and kitchenware.

Dr Jane Muncke: “There’s robust scientific evidence showing that some of these FCCs can harm human health, especially the health of the developing foetus, if they are exposed via their mothers"

Dr Jane Muncke is a co-author of the study, which started when her team compiled an inventory of 14,000 approved FCCs. They then cross-checked the scientific literature for evidence that these chemicals had migrated from food packaging, food-processing equipment, or tableware into food and, from there, into human bodies.

“We were able to show that 3,601 of these chemicals, or 25%, had already been detected in human samples, such as blood, urine or breastmilk,” Muncke says.

The health implications of the study’s findings worry her. “There’s robust scientific evidence showing that some of these FCCs can harm human health, especially the health of the developing foetus, if they are exposed via their mothers,” she says. “They include phthalates, bisphenol A and PFAS, all chemicals that can cause harm, even at low levels.”

Phthalates are found in all plastics, making them flexible, De Boer says. Bisphenol A is often used to line the inside of food and drink cans to prevent the can from corroding.

De Boer is particularly concerned about PFAS (per- and poly-fluoroalkyl substances), known as for-ever chemicals, because they decompose slowly. They remain in our environment for generations, and some are bioaccumulative, which means they build up in our bodies.

“They are known to be toxic and to affect our immune system,” he says.

Chemicals of concern

In 2023, the international Minderoo-Monaco Commission on Plastics and Human Health published a report underlining the dangers of overexposure to these chemicals. At high enough doses, phthalates, bisphenols, and PFAS in plastic disrupt endocrine function and increase the risk of premature births, neurodevelopmental disorders, male reproductive birth defects, infertility, obesity, cardiovascular disease, renal disease, and cancers.

PFAS are commonly found in food packaging because of their grease- and water-repelling properties. In 2021, the Irish environmental charity VOICE tested 23 samples of paper and cardboard packaging used by big brands and found that 12 contained PFAS.

“Take a paper cup, for example,” says VOICE’s CEO Tad Kirakowski. “It’s lined with plastic film, so it can hold coffee without disintegrating. This is a problem if PFAS transfer into that coffee and our bodies. What will happen to us as these chemicals bioaccumulate over time?”

Muncke points to studies showing that high temperatures cause chemicals to leach into food more quickly and that foods high in fat or acidity tend to absorb more chemicals from their packaging.

“That’s why I avoid plastics in contact with hot, oily, or acidic foods and never microwave food in takeaway containers,” Muncke says.

While there may be little need to fret about plastic wrap on fruit and vegetables, because they are not subjected to heat and don’t remain in plastic for long, De Boer warns consumers about the plastic that lines the inside of cans. “That plastic can contain chemicals of concern,” he says. “We know too little about them, especially their combined effects on our bodies.”

There’s a real gap in our knowledge when it comes to FCCs. A UNEP ‘Chemicals in Plastics’ report published in 2023 revealed that only 7,000 FCCs (out of the 14,000 compiled by Muncke and her team) had been tested to determine their impact on health.

“And that’s just the data gap that exists in relation to single chemicals,” says Muncke. “We know that people are exposed to mixtures of these chemicals, so it’s really the effects of chemical mixtures that need to be assessed.”

Muncke’s study also identified another potential problem with recycled material in food packaging. “Recycling mixes all kinds of paper and cardboard together,” she says. “Non-food paper products are printed with non-food grade inks and these inks remain in the paper, to some extent, after recycling.

“Because paper and cardboard are very prone to releasing chemicals into food, these non-food grade inks migrate easily. And because some of these chemicals are carcinogens, Switzerland has banned the use of recycled paper and cardboard in contact with food.”

Hazardous FCCs outlawed

Dr Karl McDonald is the chief specialist in chemical safety at the Food Safety Authority of Ireland. He explains how FCCs are evaluated by the European Food Safety Authority. “Substances and processes that are positively evaluated by the EFSA are then subject to authorisation by the European Commission in line with specific food contact material legislation,” he says.

The EU has already identified some hazardous FCCs and outlawed their use. Three phthalates were banned in 2015. 

A law is expected to ban bisphenol A from food packaging by the end of the year. In March, a provisional agreement was reached for a regulation to disallow the use of PFAS in food packaging.

There are plans to further restrict the number of FCCs that can be used, following the announcement of a revision to the European legislation on food contact materials in 2020. “In this revision, the European Commission committed to revising the existing legislation to improve food safety and public health, and to reducing the use of hazardous chemicals in particular,” says McDonald.

While we wait for new legislation, Dr Joe Kerry, of the Food Packaging and Material Science Group at UCC, has faith in the EU’s current method of ensuring that commercially used packaging for food and beverages is fit for use. “While it is true that some chemicals leach from plastics, the levels of those migratory substances have been legally set in place through legislation and followed over the years by testing to establish the maximum permitted safety levels, so as to avoid negative health issues,” he says.

Setting limits on the use of certain FCCs may sound reasonable, but De Boer points out that these chemicals are tested after they have been added to plastic or other food-contact material. “We test medicine before companies are allowed to produce it at scale, and we should do the same for chemicals,” he says. “That way, we’ll prevent problems like the one we’re currently facing with PFAS.”

Rather than worrying about FCCs, which the EU is regulating, albeit at a pace that lags behind their use in industry, Kerry believes the presence of microplastics in our food could be a bigger issue.

“We have disposed of so much plastic in our environment that our fish are swimming in seas of microplastic and plants are growing in contaminated soil,” he says. “This introduces microplastics to the food chain and scientists are now finding them in people’s bodies.”

Scientists have found microplastic in human brains, reproductive organs, placenta, livers, and blood.

“We simply do not yet know what physical effect this might have,” says De Boer.

Research is underway to find out, with two studies published this year suggesting that microplastics in our bodies could lead to cell damage, inflammation, cardiovascular disease, and an increased risk of dementia.

Because of the scale of the problem, Kerry says it’s high time to reduce our reliance on plastics. One way we can do this is by creating food-packaging materials that can be sustainably produced and composted once used. That’s precisely what his Food Packaging and Material Science Group, at University College Cork and partners at Trinity College Dublin, have been trying to do.

They are experimenting with the solid residue after apples are processed for juice and cider. “We think we might be able to make a film that could replace the plastic used to wrap bread,” says Kerry. “That could replace an entire supermarket aisle of plastic.”

Tad Kirakowski, CEO of Irish environmental charity VOICE

Kirakowski says the public wants to move away from plastic. “In VOICE’s national recycling bin survey last year, 97% of respondents said they were sick of plastic, because too much is used in packaging,” he says. “We all have to commit more to the idea of a circular economy. Manufacturers have to stop making single-use materials and consumers have to reuse and recycle.

“If we do that, by using a reusable cup instead of a disposable one for our daily coffee for example, we’ll reduce our need for plastics and our health and environment will benefit as a result.”

We should also put pressure on national and international policymakers to take action, says Muncke. “People need to realise that plastics and the chemicals contained in plastics are a problem and that they can make their voices heard so that we get better policies in place that actually protect human health.”

10 ways to reduce your exposure to packaging chemicals

As a consumer, you can take steps to minimise your exposure to the hazardous chemicals in plastics.

• Environmental scientist Dr Jane Muncke recommends avoiding hot, oily, or acidic food that has been in contact with plastic. This includes most takeaway foods and ready-made meals. High temperatures cause chemicals to leach into food more quickly, and foods that are high in fat or acidity tend to absorb more chemicals from their packaging.
• Don’t microwave food in plastic containers. Transfer the food to heat-resistant glass or ceramic containers or heat it in a pan on the hob.
• If you have a plastic electric kettle, consider replacing it with a stainless steel one, as Muncke did.
• Some teabags contain plastic, so opt for a plastic-free brand or loose leaf.
• Muncke avoids drinking from plastic beverage bottles by carrying a stainless steel refillable water bottle with her when she’s on the go. She has also disposed of all her black plastic cooking utensils, plastic chopping boards, and Teflon-coated pans. Stainless steel or cast-iron cookware is a better option than non-stick cookware, often coated with PFAS materials.

• Tad Kirakowski, CEO of the environmental charity VOICE, suggests buying fresh, unprocessed food to cut down on plastic packaging. Buying in bulk can reduce plastic packaging, too.
• Use what Kirakowski calls your “pester power.” If your chosen retailer doesn’t sell loose vegetables, for example, ask if they can provide that option. The more people do this, the more likely retailers are to listen.
• Pay attention to how you store your food. Plastic containers may contain hazardous chemicals. Glass, metal, or ceramic containers are a much safer option.
• Become more mindful of the amount of plastic you use. Kirakowski recommends looking through your recycling bin to see where most of your plastic comes from. This can help you to make more informed decisions the next time you’re at the shops.
• Lobby food businesses, regulatory bodies and politicians to change the laws regulating food packaging. If these are made more stringent, hazardous chemicals won’t contaminate our food in the first place.