‘Compostable plastic’ sounds like the ideal solution to the world’s plastic waste management problem. Coupled with the decentralised waste management model in force abroad – and increasingly being implemented in India – the idea that plastic can be tackled at the home or community level sounds idyllic.
But is this really possible? A UK study found that some plastics are compostable in name only.
According to a UK-wide study, 60% of home-compostable plastics do not fully decompose in home compost bins and end up in our soil. The study also discovered that citizens are perplexed by the labels of compostable and biodegradable plastics, resulting in improper plastic waste disposal. These findings highlight the importance of revising and redesigning this ostensibly sustainable plastic waste management system.
Global plastic pollution is still one of the most serious environmental issues of our time. According to a new Organization for Economic Cooperation and Development (OECD) report, plastic consumption has quadrupled in the last 30 years. Only 9% of plastic waste is recycled globally, with the remaining 50% ending up in landfills, 22% evading waste management systems, and 19% being incinerated.
In response to the pollution crisis, several countries have set goals of eliminating all single-use plastics by 2025 and making plastic packaging 100% recyclable, reusable, or compostable.
Compostable plastics?
Compostable plastics are becoming more common as the demand for environmentally friendly products grows. Compostable plastics are commonly used in food packaging, bags, cups and plates, cutlery, and bio-waste bags. However, these types of plastics have some fundamental issues. They are largely unregulated, and environmental benefits are frequently exaggerated.
On the other hand, compostable plastics are currently incompatible with the majority of waste management systems. There is no internationally agreed-upon standard for home compostable plastics. When these plastics are discarded or sorted for recycling, their fate is either incineration or landfill. The typical fate of landfill or incineration is not usually communicated to customers.
In the range of UK home composting conditions, compostable packaging does not break down effectively, resulting in plastic pollution. Even packaging certified as home compostable does not degrade effectively. The question of whether compostable plastics can help to solve our widespread plastic pollution problem remains unanswered.
Compostable plastics are potentially useful for products that are not suited to recycling due to contamination such as tea bags, fruit labels, take-away food packaging, and certain hygiene products. These products typically end up in landfill.
The study shows that home composting, being uncontrolled, is largely ineffective and is not a good method of disposal for compostable packaging.
On the whole, there is a requirement for the improvement and advancement of home compostable plastics. The idea that a material can be sustainable is a widespread misconception. Only a system of production, collection, and reprocessing of a material can be sustainable.
Big Compost Experiment
Danielle Purkiss and her colleagues designed The Big Compost Experiment, a three-part citizen science study, to investigate what the public thinks about home compostable plastics, how we deal with them, and whether they fully degrade in our compost.
First, participants from across the United Kingdom completed an online survey about their attitudes and behaviours toward compostable plastics and food waste. Following that, participants were invited to participate in a home composting experiment. Finally, those who took part in part two were asked to look for traces of their chosen compostable plastic items in their composter. The data was gathered by the researchers over a 24-month period.
“Our study was created in response to feedback from the public and stakeholders from industry, policy, and third sector organisations, which highlighted many systemic issues in the manufacturing, use, and disposal of compostable plastic packaging,” explained Purkiss.
The findings indicate an overall willingness to make environmentally friendly choices by purchasing compostable plastics. Participants, however, expressed confusion about the labelling and identification of these plastics. The researchers discovered that 46% of a randomised sample of 50 item images showed no identifiable home composting certification or standards labelling and 14% showed industrial composting certification.
“This shows that there is a current lack of clear labelling and communication to ensure that the public can identify what is industrially compostable or home compostable packaging, and how to dispose of it correctly,” said Purkiss.
The experiment revealed a shocking result that 60% of plastic certified as home compostable did not fully disintegrate in home compost bins.