Biodegradable and compostable are not interchangeable terms. What should you know about them, and which should you choose?
Biodegradable plastics refer to petroleum-based plastics that are combined with an additive that makes them break down quickly.
One laboratory study studied everyday products made from bio-based and/or biodegradable materials, including disposable tableware, chocolate wrapping, drink bottles and wine corks. Findings showed that 75% contained chemicals that are ‘toxic’ in vitro. Bioplastics contain up to 20,000 chemicals, with cellulose and starch-based products containing the most chemicals. The study showed that the overall toxicity increases from the raw material to end product, suggesting that new substances are added or generated during manufacture.
Whether something is biodegradable or not is also based upon certain conditions being met at end of life – home consumers cannot meet these requirements, and often the places where these items end up cannot either.
Compostable means something which will degrade into carbon dioxide and water. Home compostable means you can compost the item in your home compost – but that still relies on the correct conditions being met.
Waitrose supplies home-compostable produce bags, and the Co-op carrier bags are also home-compostable. Compostable items suitable for a garden compost should have the EN1342 seedling logo on which means they will break down at the same rate as food and garden waste.
Anything other than bags, compostable coffee cups for example, will not compost in a home setting.
So – biodegradable or compostable items without the leaf logo should be treated the same as any other waste and put into a general waste bin.
Compostable is only home-compostable if it bears the leaf logo and you compost properly.
Biodegradable is just swapping one kind of single-use plastic for another.
For shopping, removing the packaging entirely would be the best option, and taking re-usable cotton, hemp or muslin bags, or other suitable containers to the supermarket.