Transcript

[MUSIC PLAYING]

CARL BOARDMAN

At the moment in the United Kingdom, when we shop at supermarkets like this, we are currently using over eight billion single-use carrier bags a year, which equates to approximately 60 000 tonnes of plastic – or about 130 bags per person.

Most single-use carrier bags – like this one here – are made out of fossil fuel derived polyethylene, and was subject to a five pence levy in Scotland, Wales, and Northern Ireland – and in the near future England, too. The UK government is expected to amend this policy to include an exemption for new, innovative biodegradable carrier bags, which is where our research at The Open University comes in where we develop biodegradable polymer films, such as this one here.

Here at The Open University, we’re helping UK industry develop new biodegradable plastic carrier bags and packaging materials. When developing biodegradable plastics, our target is for materials to lose 90% of their carbon content within less than one year whilst at the same time having no toxic properties.

In our labs, we’re working in partnership with DEFRA and a UK polymer company to undertake a series of biodegradability and ecotoxicology experiments and tests. To do this, we use instruments, such as this respirometer, which measures the breakdown of plastic materials through the evolution of carbon dioxide. This setup is currently simulating idealised composting conditions.

Within each of these vessels, we have a compost type material and plastic carrier bag film cut up into tiny pieces so the two mediums can interact with one another. Because it’s idealised, we have high temperatures and constant aeration through these inlet and outlet tubes here, which feed directly into our gas analysers. In this instance, measuring a high amount of CO2 from the compost and plastic mix indicates biological breakdown and a positive result.

Today’s carrier bags mainly end up in landfill sites, but many evade waste treatment and recycling processes altogether and end up littered all over the countryside, or perhaps more worryingly, in the world’s oceans. The world’s oceans are currently estimated to contain over five trillion pieces of plastic – or put another way, about 270 000 tonnes. Here, plastics represent a threat to animals through entanglement, choking, and poisoning.

So in the future, bags that we’ve helped develop will avoid the five pence levy and have a reduced environmental footprint as well.