Are plastic containers safe for our food?

The industry claims its containers are safe, but some experts point to a lack of data and warn that plastic and heat are not a good combination.

Many of us have a kitchen cupboard overflowing with plastic containers to store our leftovers.

But as awareness of the health and environmental hazards of plastic grows, some consumers may be wondering: is it time to ditch those old deli containers?

Of all the plastic waste ever produced, only 9% is recycled. From its contribution to global warming and pollution to the chemicals and microplastics that migrate into our bodies, the food chain and the environment, the true cost of this cheap material is becoming more and more apparent.

Thousands of compounds are found in plastic products throughout the food chain, and relatively little is known about most of them. But what we do know about some of the chemicals in plastics is worrying.

Phthalates, for example, are used to make plastics more flexible and are found in food packaging and cling film, and the US Centers for Disease Control and Prevention (CDC) has found measurable levels of phthalates in the US population (including in the body of Guardian journalist Emily Holden). In animal studies, they have been linked to reproductive dysfunction and some researchers believe they are associated with reduced fertility, neurodevelopmental problems and asthma in humans.

As well as toys and car parts, water bottles and tinned food, bisphenols have been found in DVDs and CDs.

Bisphenols: what to know about the chemicals in water bottles and cans

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Bisphenol A, another chemical widely added to food plastics, has come under increasing regulation after research linked the chemical to brain and reproductive harm in newborns and babies. But BPS and BPF, two common alternatives used in products marketed as "BPA-free", may have similar effects to their predecessors: studies at the University of Texas and Washington State University found that even at doses of one part per trillion, BPS can disrupt cellular function. A 2019 study from New York University linked childhood obesity to BPS and BPF.

Many other chemicals are added to plastics during the manufacturing process, and researchers acknowledge that there are still many gaps in our understanding of how they affect health and development. However, concerns about this 'wonder material' are growing.

What's in those takeaway containers?

Food containers are just one link in a vast chain of plastic products that touch what we eat, from coated conveyor belts on food production lines to disposable clamshells for delicate berries, clear carrot bags and milk jugs.

Researchers say it is difficult to answer which plastic containers are safe without increasing the transparency of which chemicals are in everyday plastic materials.