Biodegradable and compostable plastics fact sheet
What does biodegradable mean?
If a material is biodegradable, it can be broken down by living microbes such as bacteria or fungi, which use it as a food source, with carbon dioxide and possibly methane generated as by-products.
The biodegradation of materials can take anywhere from weeks to many years, depending on environmental conditions such as temperature, moisture, oxygen levels and the types of microbes present.
For example, newspaper can break down completely within weeks in a compost bin, yet as studies have shown, it can also remain intact and readable after decades in landfill.
Degradable, oxo-degradable, and oxo-biodegradable plastics
Supplier claims about regular plastics that have been made biodegradable by using additives have caused further confusion.
Testing has shown that while these additives accelerate the degradation of plastics, they cause plastic to fragment and create microplastics, which are also harmful to the environment.
It’s important to note that fragmentable plastics may only fully biodegrade under very specific environmental conditions. If products are disposed of in landfills, or if they enter the marine environment due to littering, then this breakdown process is unlikely to occur.
Under the updated 2022 National Plastics Plan, the Australian Government agreed to phase out plastic packaging with additive fragmentable technology because they do not meet the standards listed below. HSV has adopted the same principle for plastic consumables and packaging.
Comments on waste management of plastic consumables and packaging
Recycling is the most environmentally sustainable method of waste management for plastics.
Compostable plastics can be a good option if they can be included in compost waste collections. However, currently most service providers do not accept compostable plastics in food and organic waste collections.
Clinical consumables made from plastics are unlikely to ever be accepted in food and organic waste collections, even if the product used is certified as biodegradable plastic. While sending plastic waste to landfill is not ideal, it is a safe way to manage plastic waste used in healthcare that cannot be recycled.
HSV specifications for certified biodegradable and compostable plastics
Australian standards determine which plastic items (products or packaging) are both biodegradable and compostable. They are:
- AS 4736-2006 Biodegradable plastics - biodegradable plastics suitable for composting and other microbial treatment.
- AS 5810-2010 Biodegradable plastics - biodegradable plastics suitable for home composting.
Testing against these Australian standards should be carried out by a recognised independent and accredited testing laboratory, and preferably certified under the Australasian Bioplastics Association verification scheme.
Only plastic products that meet one of the above standards with a certified testing report will be accepted as a biodegradable product by HSV.
HSV may provisionally accept certified evidence that a product meets European standards EN 13432:2000 (Packaging) or EN 14995:2006 (Plastics) pending provision of a certified testing report to one of the Australian standards above.
Further reading
Information about bioplastics, biodegradable plastics and compostable plastics is available from the Australasian Bioplastics Association, the peak industry body for manufacturers, converters and distributors of bioplastic products and materials throughout Australia and New Zealand.