Are bio-plastics the solution to plastic pollution?

As many cafes, bars and shops look to tackle their single-use plastics output, they are choosing alternative ‘bio-plastic’ materials. But are these materials solving the plastic problem or creating new ones?

The major issues with plastics ending up as litter is that they can cause injury to mammals and birds, who accidentally get caught up or ingest them. They leach out chemicals which bio-accumulate and affect the hormones and reproduction of fish and mammals; and every piece of plastic that has ever been made still exists.

Straws are among the most common plastic items found on UK beaches – they make up over 60 per cent of all the litter found there. Photo credit: Alexander Mourant.

And what about the alternatives? In regards to marine litter, a compostable fork that can hold its heat to 85 degrees, won’t don’t do very well at decomposing in cold ocean water. And Peter Jones, Principal Consultant at Eunomia is concerned that “they could encourage littering if people think they ‘biodegrade’  in the natural environment”. When looking at the websites of bioplastics suppliers, most of them don’t suggest they resolve the issues of plastic litter; although the explicitness on what biodegradable or compostable means varies greatly. Many do recommend paper straws over compostable plastic ones, as of course, a compostable straw could still end up in a turtles nose whereas paper really does break down on contact with water- generally as you are drinking with them.

So what is the benefit of these plastic alternatives? In considering any materials it’s essential to look at how it’s made, used and where it could and should end up.

Traditional plastic production uses the same amount of oil, 6%, as the aviation industry and if production continues to increase, it is set to overtake the 12% carbon emissions of aviation by 2050, so finding alternatives or stopping the demand for single-use plastics is essential. However, as Senior Consultant, Ed Cook from Resources Futures points out “Not all bioplastics made from organic material are biodegradable, and some bioplastics which are biodegradable, are made from oil-based ‘fossil’ material.”

Oxy-degradable plastics, typically plastic bags and straws, are made from oil-based plastics that break down in air and sunlight into small micro-plastics, so these are really bad news if they end up as litter. In fact, the EU Environment Committee is extending proposals for the ‘Plastics Strategy’ by calling for a “complete ban on oxo-degradable plastics by 2020”

In contrast, compostable plastics or PLA, are made from corn-starch and bi-products from the sugar cane industry. However, unlike fruit and veg composting, compostable plastics require industrial composting with high heats to break down within 90 days. But not every composting process is suitable. In Bristol, the anaerobic digester where our food waste goes can’t process them, as it works in a different way so won’t get the heat required and the process is quicker than 90 days. The nearest appropriate ‘in-vessel composter’ is in Gloucester and one producer, Vegware is trialing a ‘close the loop’ project with their Bristol customers including Bristol University to ensure the materials actually get composted.

Compostable serveware requires commercial composting

For households wondering what to do with PLA pots or takeaway dishes, where a supplier doesn’t offer a return scheme, the advice from both Vegware and Geneco (who run the anaerobic digestor) is to put them into general waste, where they will most likely go for ‘Waste to Energy’.  It seems the best scenario for compostables to actually get composted is what Vegware describes as enclosed sites such as, “cafés and restaurants in universities, office buildings or zoos”, or events like Chalfest in Gloucestershire who separate out their food waste and compostable packaging for collection to an in-vessel composter.

Compostable serveware including plastic cups and food on it’s way to the in-vessel composter from Charlfest 2018

One of the current challenges with this is that compostable plastics look very similar to oil-based plastics, so it is hard for consumers and processors to know which is which and of course a processing plant won’t want to risk contaminating their compost with oil-based plastics. There is also the concern that these plastics, if they end up in recycling, can contaminate recycled plastic, although the bioplastics industry are quick to refute that claim. The recent plastics report by Resource Futures, suggests that the producers and waste processors need to “work together to agree the role these materials play and how they are managed alongside other plastic materials, in order to avoid potentially introducing significant issues”.

As with plastic recycling, it seems that the solution to plastic pollution and litter is not as straightforward as switching materials. Really the only solutions are looking to remove the item completely, find a reusable option so people don’t want to discard it or choose something that really does degrade as it’s being used. And for bars and cafes looking to reduce their single-use plastics output considering materials on how they are being used and where they could end up is essential.

This article is part of a six month series on waste, investigating what is happening at a local and national level and where Bristol businesses and residents can get involved to make change .

Find about how Bristol’s drinking venues are tackling plastics visit: b247.staging.proword.press/business/news-business/dont-be-a-sucker-giving-a-sip-about-drinking-apparatus-in-bristol

Get some advice on tackling your business waste visit: b247.staging.proword.press/lifestyle/environment/tackling-your-business-waste/