Let's start with getting to know degradable and biodegradable.
Degradable is the more muddy and vague term. All it is referring to is that it will break down without any reference to time frame or what it will degrade to. This is often microplastics that will eventually end up in the ecosystem, our food chain, and us.
Due to the growing issues of plastic pollution, biodegradable plastics have increased in circulation over the last couple of decades. The term biodegradable means that the plastic can be broken down completely into water, carbon dioxide and biomass or compost. Great, huh!
However when looking at this more closely, it becomes a little more problematic.
For it to break down in a reasonable time frame (months instead of years) the plastic needs to be exposed to the right bacteria and the right conditions (usually extreme heat). This is something that may not happen if disposed of in less than ideal conditions.
Bioplastics Australia has recommended that Biodegradable products should feature a clear recommendation regarding the suitable end-of-life option and correct disposal for this product.
Not all biodegradable products are compostable. It's important to know that bio based products may not be compostable due to alterations and additives during the manufacturing process. The label biodegradable means the product can’t just break down into smaller pieces of plastic, but it doesn’t dictate anything about leaching chemicals into the environment, or specify how long it will take to break down in imperfect conditions.
Landfills are generally horrible conditions for biodegradation and can cause the production of methane gas during the degradation process - causing way more pollution than carbon dioxide. The very term “biodegradable” is so confusing that it leads people to assume it still biodegrades regardless of how it’s disposed of.
Now Let’s talk about the compostable
All compostable packaging is also biodegradable. But the reverse is not true.
Composting is a way of controlling the rate of decomposition or biodegradation. Composting uses specific conditions to control moisture, temperature, and oxygenation to optimize microbial action.
This means that products that are biodegradable go from breaking down in 6 months - 1000 years, to only 90 days in a compost.
The process of composting must not harm, but benefit the environment. This means it must be able to support plant life, leave no toxic residue and be consumable by worms.
Over the last decade, scientists have developed test methods that can verify whether something can fully biodegrade in a reasonable time frame without leaving any residue.
There are two voluntary Australian Standards for compostable packaging (AS 4736 and AS 5810). These outline four requirements that must be met to be classified as compostable:
- Ecotoxicity
- Fragmentation
- Biodegradability
- Compost quality
AS 4736-2006: The general standard of a plastic being “suitable for composting and other microbial treatment”. These generally need to be exposed to the higher temperatures of an industrial composting facility. This is where our pods sit!
AS 5810-2010: Verification for plastics that are home compostable.
To make things simple we should really be calling any plastic capable of safely biodegrading. compostable. Labeling things as biodegradable is far too ambiguous to be helpful.
