On the eve of a ban on single-use plastic bags, a researcher has warned how toxins from plastic and other packaging are leaching into our food and drink.

Massey University environmental anthropologist Dr Trisia Farrelly, who recently attended an international conference focused on contamination from plastic, was also urging people not to reuse plastic for packing or storing food.

A recent report suggested people today were consuming about 2000 tiny pieces of plastic every week – that's equal to five grams, or the weight of an Eftpos card - and adds up to 21 grams a month, or just over 250 grams a year.

As our understanding of the risk of these microplastics getting into our food became more widespread, so to would our knowledge of certain industrial chemicals to avoid.

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Farrelly said consumers were already seeking out food and drink containers that were free of Biphenol A, or BPA.

"Unfortunately, industry has found loopholes by using alternatives in 'BPA-free' bottles by simply using other bisphenols - such as BPS - which are even more harmful than BPA."

She said people should also be on the lookout for per- and poly-fluoroalkyl substances, or PFAS, which were synthetic chemicals used in a wide range of industries and consumer products.

Most people have been exposed to them – there are around 3000 types – and they do not break down and go away.

"What's most disturbing is that PFAS are used as a moisture barrier in cardboard and paper used in food packaging, such as pizza boxes. They are also used in non-stick cookware."

Farrelly also singled out non-intentionally added substances, or NIAS - toxicants introduced through recycling process.

These included chemicals such as flame retardents, dyes and additives, and are "deeply concerning," she said.

"Every time you recycle plastic it degrades producing more and more NIAS."

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Research had shown that these toxicants could act as endocrine disrupting chemicals, which were hazardous at extremely low doses and had been implicated in a wide range of disease including cancers, obesity, fertility problems, male impotence and heart disease.

Farrelly further called for new industry guidelines around using recycled plastics.

"Never use recycled plastic for food packaging or storage unless you undertake a number of stringent steps – an improved sorting process, a super clean recycling process, creating functional barriers between your food and food packaging, and ban toxic chemicals used in food packaging," she said.

"Industries need to rethink what they are delivering our food in," Massey University's Dr Trisia Farrelly says. Photo / File

"The global plastic pollution crisis is not just about the environmental impacts anymore, it's not just about climate change anymore, it's also about our health – and the health of the soil and the plants and animals we eat, the water we drink and the air we breathe."

She suggested the problems could be overcome through changes across New Zealand's food packaging, retail, and recycling industries.

"Multi-layer food packaging - like Tetrapak - should be banned, as should all expanded polystyrene, and all single-use food packaging should be phased out," she said.

"We also need eco-labelling. Consumers should be informed which tin cans have plastic linings and which don't, particularly if you don't want BPA in your tinned tomatoes or coconut milk.

"I want to know at a glance if an independent body considers my food packaging high, medium, or low risk so I can make an informed purchase."

She saw an opportunity for developing new non-toxic packaging made from locally-sourced materials, such as starch from potato peelings or cellulose from forestry waste like bark, hemp, or flax.

"I don't have all the answers but we need to exercise precaution now that we have more information, and we know industries need to rethink what they are delivering our food in, and the implications for the health of all New Zealanders."

WHAT YOU CAN DO

• Choose glass and stainless steel over plastics.

• If you must use plastics for food storage, avoid, heating them or using them in microwave ovens or dishwashers.

• Don't store acidic or fatty foods in them to avoid toxins from the plastics leaching into food and drink.

Next month is Plastic Free July. Find out more here.