Many of us are more likely to purchases a disposable product (like a carrier bag or coffee cup) if it carries the label ‘biodegradable’, but do these labels mean the products actually break down? There’s a danger that the increase in man-made ‘biodegradable’ products is simply justifying an increase in single-use products.
It’s an easy assumption to make that a ‘biodegradable’ plastic bag is preferable to a traditional one, but the hard work is done once it has been disposed of, and in many instances ‘biodegradable’ products end up in landfill anyway and never break down.
What Does ‘Biodegradable’ Mean?
The definition for biodegradable is a substance or object that is capable of being decomposed by bacteria or other living organisms, thereby avoiding pollution.
The EU defines a biodegradable product as one that breaks down within 12 weeks, leaving no more than 10% of the original material in pieces bigger than 2mm. Additionally the product must not cause excessive damage to the soil composition or structure as it breaks down.
However, research into a number of biodegradable products has found that many items described as ‘biodegradable’, particularly plastic bags, coffee cups and makeup wipes aren’t composted correctly, and can end up in landfill where they don’t break down at all.
When Biodegradable Isn’t Biodegradable
Biodegradable items fall into two categories:
- Items that can be completely broken down in nature, like fruit, vegetables and brown paper bags
- Man-made packaging including biodegradable versions of nappies, coffee cups and makeup wipes.
Man-made biodegradable products can be broken down by microbes, turning them into biomass, water and carbon dioxide. But this process is only possible in a very controlled set of circumstances within an industrial compost heap that provides the right temperature and microbes. A home compost heap can’t replicate these conditions.
But if bioplastics are not put through an industrial composting stream and instead end up in landfill (which they will even if placed in recycling) they will not break down at all, and instead will disintegrate into smaller pieces of plastic that leach into waterways and soil.
The road to country-wide use of bioplastics is a bumpy one. At the moment in the UK we are ill-equipped to effectively compost meaningful volumes of biodegradable plastic. At present there are only 170 industrial composting facilities in the UK . This means more ‘biodegradable’ products end up in landfill than are recycled each year.
This means that for now it’s still better to avoid single-use products where possible and stick to the three R’s - Reduce mainly, Reuse as much as possible and Recycle only when really necessary.
Next Gen Biodegradable Plastics
There is some hope for the future. Recently bioplastics have been developed from industrial vegetable offcuts and peels which can be fed to microbes that then produce the material that can be processed into bioplastics. The University of Wolverhampton has even figured out how to do this by feeding the microbes old cooking oil and even polystyrene! This creates a circular system for single use plastics.