Biodegradable v Compostable

There is so much confusion around what is degradable, biodegradable and compostable.  We have previously written about degradable v biodegradable, so let's also look into compostable as they are three completely different things.

1.  Anything that has come from the ground is likely to be compostable, such as fruits and vegetables.  

2. Anything that can break down into organic matter is biodegradable, such as fruits and vegetables as well as paper, animal excrement and other plant based materials.  

3. Anything that over time breaks down into small particles is degradable, this is almost everything, over time, and can include plastics.  

For something to be a compostable, the material must break down into soil conditioning material not just organic material.

Bio plastics that are compostable are also biodegradable, but not every plastic that is biodegradable is compostable. Compostable plastic refers to biodegradation into soil conditioning material under a certain set of conditions in a specific time frame. 

So this brings us to compostability - industrially compostable and home compostable. Some things are only able to break down in the perfect conditions of a commercial compost facility where microorganisms and heat are used and the resultant chemicals that can be harmful to the environment are captured.  Certified home compostable bioplastics have been made to breakdown without the need for the specific microorganisms and high temperatures of an industrial compost.

Biobased plastics are made from plant materials instead of being made from oil, or petroleum. Because they are plant based, we tend to assume that it is biodegradable, however, some biobased plastics can be designed to be structurally identical to petroleum based plastics, if they are made this way, they can last for the same length of time. 

The ability of biobased plastics to be recycled varies. Some forms of biobased plastic cannot be recycled together with petroleum-based plastics due to chemical structure incompatibility, while other biobased plastics may have compatible chemical structures that allow for recycling together with petroleum-based plastics. In order to determine what waste disposal options are available for a biobased plastic item, it is necessary to read the product’s label as to its compostability and recyclability.

So what does all this mean? 

For a home consumer look for Certified home compostable AS5810.  

If the bioplastic is only commercially compostable it will be AS4736 certified. In Australia residential consumers don't have easy access to these yet so best to avoid these if possible.

Home compostable bioplastics and commercially compostable bioplastics typically won't be recyclable so they cannot go in your soft plastic recycling. They need to go into your organic waste bin (if you have one) or home compost.  For home composting check out the amazing Subpod in our online store.

Leave a comment

All comments are moderated before being published