Let’s start with a simple question:
What exactly are commercially compostable products?
Commercially compostable products are made of bioplastics.
Bioplastics are not naturally present in the environment. They are made from components which are biobased.
Biobased means the material or product is either in full or in part derived from biomass (plants), compared to traditional plastics that use fossil fuel.
Biomass used to produce bioplastics may be from corn, sugarcane, cassava or cellulose for example.
In 2018, National Geographic stated,
“Bioplastic simply refers to plastic made from plant or other biological material instead of petroleum. It is also often called bio-based plastic. It can either be made by extracting sugar from plants like corn and sugarcane to convert into polylactic acids (PLAs), or it can be made from polyhydroxyalkanoates (PHAs) engineered from microorganisms. PLA plastic is commonly used in food packaging, while PHA is often used in medical devices like sutures and cardiovascular patches.”
On the market today, “compostable products” refer to these bio-based products. For example: compostable bags, coffee cups, cups, straws, plates, containers, etc.
This article goes into more detail on “Better understanding compostable packaging in 2021”.
How can you recognise commercially compostable products and where can you dispose of them?
If nothing else is stated on the packaging, “compostable” usually means “commercially compostable”.
Generally, it also means the brand registered and received a certificate proving that its products are accepted in commercial/industrial composting facilities.
To decompose and biodegrade a bio-based product, such as a compostable cup, it needs to be exposed to high temperatures (around 55 to 60 degrees Celsius), sunlight, oxygen and high humidity. These are the only conditions under which the compostable component of a product will break down into biomass again and become a nutrient rich compost.
These conditions are met only in specific commercial/industrial composting facilities.
To end up in these facilities, these compostable products should go in the organic green bin, along with food and garden waste.
The commercially compostable certification is also the only way for commercial composting facilities to accept these products in their facilities for full biodegradability.
According to the Australian Bioplastics Association,
“the Australian Standard for Industrial Composting AS4736 and for Australian Standard Home Composting to AS5810- are required to disintegrate after 12 weeks and completely biodegrade after six months. That means that 90 percent or more of the plastic material will have been converted to CO2. The remaining share is converted into water and biomass, which no longer contains any plastic. AS4736 and AS5810 also include tests on ecotoxicity and heavy metal contents to ensure that no harmful substances are left behind.”
But what happens if they don’t end up in a composting facility?
The short answer is: nothing. They behave in exactly the same way as traditional plastic.
Even worse, they can break down into micro-sized pieces that can last for decades and endanger marine life and the ecosystem.
- If they end up in the environment, they will add up to the 130 000 tonnes of single-use plastic dumped every year into our environment (source: WWF Australia in SBS News)
- Same result if the products end up in our landfill – they will not decompose in those conditions
- If they end up in a recycling bin, they will contaminate the stream. It complicates and slows down the sorting processes at the facilities. The molecular structure of bio-based plastic does not allow them to be recycled into new plastics. Hence why it’s very important not to confuse them with traditional plastic, although they look very similar!
Bio-based or compostable plastics can become a new source of pollution if they are not disposed of properly.
In Australia, the only way to dispose of them is in one of 150 composting facilities that will ensure a full and safe break down.
In short, to be able to use and dispose of commercially compostable packaging safely, you need:
- An organic green waste collection
- An organic green waste collection that accepts compostable packaging—some States/Councils only accept garden waste, for example
- A composting facility available in your area. You can find out whether a composting facility is available near you in the following link: https://www.aora.org.au/find-a-composter
If these three criteria are not available to you, it’s safer to stay away from these commercially compostable products and instead use home compostable or reusable packaging.
Click here to read my latest article on “Better understanding compostable packaging in 2021”.
Marion Vigot
About the author:
Marion is a French entrepreneur, profoundly interested in the composting industry. Her words are her own thoughts and come from her research and learning. Although she quotes and sources the information she shares, Marion is not a scientist or a researcher and her opinions should not be understood as a scientific truth.
Through her findings and experience in the industry, she is attempting to support hospitality businesses and producers in their search of alternative choices to single-use and other types of plastic packaging. You should always do your own research to best inform yourself.
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