'Biodegradable' vs 'Compostable' - What's The Difference?
Biodegradable, compostable… the two have become buzzwords over recent years and are often being used interchangeably. But are they really the same, or is there a difference between the two terms (spoiler alert – there is a BIG difference)?
In a world where companies like to use environmentally friendly sounding words as selling points and marketing moves, it’s important to know exactly what every term refers to and how to check if a product is truly sustainable.
What does it mean when something is biodegradable?
Something that is biodegradable will eventually break down into smaller and smaller pieces as a result of a natural process. However, there is no given timeframe in which this has to happen for something to be considered biodegradable. Therefore, many very unsustainable materials (including plastic) can be labelled as biodegradable even if they are detrimental to the planet. This is also the case for ‘eco-friendly alternatives’ such as wheat straw, corn starch and rice husk. The particles that a material falls apart into could very well be toxic and harmful to the environment.
Something that is biodegradable is not necessarily compostable, or even close to being sustainable.
What does it mean when something is compostable?
Compostable materials, on the other hand, break down into completely non-toxic components that are not environmentally-damaging, given the right conditions. The time that it takes for a product to break down depends on the environment it’s breaking down in – some can be composted in a home composter, and some may require the conditions of an industrial composting facility. These industrial composting facilities provide higher levels of heat, oxygen, water and micro-organism activity – conditions which cannot be achieved in a home compost.
How to recognise a compostable product?
Any product can be labelled as biodegradable, but that is no proof of its environmental sustainability. For a product to be labelled as compostable, on the other hand, it needs to be able to decompose in an industrial composting facility within 180 days. There is a wide variety of different certifying bodies for compostable products, depending on where you’re located.
TUV labels are best to look out for, as products awarded with them undergo a high level of monitoring and scrutiny. All of the compounds a product decomposes into are tested for even minor levels of toxicity and completion of decay. In Europe, products that pass this analysis are labelled as certified EN 13432 compliant. In the U.S., those products are labelled as ASTM D6400 compliant. However, in the US, the Biodegradable Products Institute (BPI) is the most well-known certification symbol to look for and requires ASTM D6400 compliance along with additional testing results. In Australia, the Australian Bioplastics Association (ABA) provides testing of polymer materials. The successfully certified are labelled as compliant with AS4736 and carry a seedling logo.
When buying products claiming to be sustainable, always look out for what messaging is used. Does the product merely have the word ‘biodegradable’ written on the packaging, or is it compostable? Don’t be fooled by brands and marketers greenwashing their products to make a profit by influencing customers who are simply trying to make a better choice.
The best thing you can do is to continuously grow your awareness, learn what materials are compostable, ask questions and use your voice. The change starts with us.