Landfill-Biodegradable Everyday Plastic
When it comes to biodegradable plastics, the 2 main choices are:
1. Landfill-biodegradable (which is our choice)
2. Compostable (home or commercial
How long it takes to biodegrade
‘Compostable’ plastic are bioplastics made from one of the following materials:
- Bacteria produced plastics
- Plant-based materials
- Starch-based plastics
- Soy-based plastics
- Cellulose-based plastics
- Lignin based plastics
Compostable plastics are a subset of bioplastics that will biodegrade under specific composting conditions hence not all bioplastics are compostable.
Bioplastics can be divided into 2 groups:
- Bio-based plastic that is biodegradable
- Bio-based plastic that is NOT biodegradable
To be considered ‘biodegradable’ means it can break down into the water, carbon dioxide, methane, and biomass in a given time frame (dependent on different standards).
This is where a lot of confusion exists, and “greenwashing”. Some people think that bioplastic will automatically be biodegradable, however, that is not the case. For example, polyethylene plastic can be made from sugar cane, but it is no more biodegradable than polyethylene made from petroleum.
Although the manufacturing of bioplastic materials is reliant upon petroleum as an energy and materials source, it is generally regarded as a more sustainable activity (due to carbon sequestration, as the plant grows) compared to petroleum-based plastics.
Similar to commercial compostable plastics, home compostable plastics have an extra component in them, PBAT* which is a highly biodegradable material. This allows home compostable products to biodegrade in cooler temperatures such as home compost bins or landfills. Their biodegradation rates are longer than commercial compost facilities but still relatively fast being several months up to 1-2 years depending on the plastic thickness.
Biogone’s home compostable products will biodegrade in a home compost, commercial compost facility (if the waste stream is available) or landfill. Certified for home compostability in accordance with Australian/NZ standard AS5810.
Benefits of home compostable products:
Can be disposed of in a commercial compost facility (if available), home compost pile, or rubbish bin destined for landfill. They can also be disposed of in some council green bins where permitted. Enquire with your local council.
Will biodegrade in anaerobic conditions in a landfill. The latter condition allows their internal energy (methane) to be captured, which can also be used to generate electricity.
Note neither compostable nor home compostable plastics are recyclable. Their material will not mix with conventional plastics.
Product: Biogone Home Compostable Dog Poop Bag
*PBAT (polybutyrate adipate terephthalate) is a biodegradable random copolymer. The co-polymer is available commercially as resin and as a compound with PLA or starch. Today, the building blocks are made from petrochemicals. As a “drop-in” polymer, PBAT resembles LDPE in its properties. The flexibility and toughness of this polymer make it ideal for blending with another biodegradable polymer that is strong and rigid.
These are bioplastics that biodegrade under commercial composting conditions as per AS4736. Currently in Australia there are several limitations for commercial compostable plastics that make them not a sustainable option because:
- For a compostable plastic to biodegrade it must be in a commercial compost facility with temperatures of 60 deg C, plenty of oxygen and good moisture levels. If those conditions are not met, the compostable plastic will not biodegrade as the microorganisms need those conditions to live.
- Due to their different composition, compostable plastics cannot be recycled in the mainstream soft plastics. Their materials have different properties and would contaminate other conventional plastics if they were mixed together. If they cannot be delivered to a commercial compost facility, they need to go to a landfill.
- There are no separate recycling facilities that will sort out the compostable plastic from other plastic waste. This means by default a compostable plastic will generally go to a landfill where it will not biodegrade.
- There are very few commercial compost facilities in Australia, making it very unlikely that commercially compostable plastic will ever be transported there.
- When a commercially compostable plastic biodegrades its gaseous by-product is CO2, which cannot be used for energy capture methods to generate green electricity (as opposed to the CH4 generated from landfill-biodegradable plastics).
Products displaying the Home Compostable certification logo (AS5810-2010) are certified by the Australian Bioplastics Association as biodegradable and compostable, in a home compost. Whilst all home compostable products are themselves home compostable, their contents may not be. Make sure that the contents of your home compostable bag are also home compostable and if they are not, dispose of everything to a general waste bin (destined for landfill) where the home compostable bag will still completely biodegrade. Some examples of contents that may not be home compostable include pet waste and general household waste that is placed into a home compostable bin liner. Not all councils accept biodegradable plastics in their green waste bins, so double check what is accepted before disposing of your waste. If in doubt, all home compostable bags will completely biodegrade in a landfill.
No. However it’s best to check if your council accepts compostable packaging in the kerbside green waste bin. In terms of dog and cat poop, it’s best to dispose of it in a pet poop compost (if available) or in the rubbish bin (landfill).
A home compost is your home compost 🙂 This is where you can dispose of green or food organic waste at home. Commercial compost facilities accept kerbside food and green organics, from a green bin at home. The waste is taken to a facility where the temperature, moisture, and oxygen levels are monitored to create a formal biodegradation process.
All bioplastics will not biodegrade in water alone. They need home or commercial compost conditions (i.e. an abundance of microbes to digest the plastic). Also, bioplastics should be disposed of in the correct waste stream (not in our oceans, waterways, or parks).
No. For a ‘compostable’ plastic to biodegrade it must be in a commercial compost facility with temperatures of 60 deg C, plenty of oxygen and good moisture levels. If those conditions are not met, the compostable plastic will not biodegrade as the microorganisms need those conditions to live.
Depending on the plastic thickness and the home compost temperatures, the home compostable product can start biodegrading within 4-8 weeks and up to 1-2 years. The Australian/NZ standard AS5810 means products must biodegrade within 12 weeks.
According to the ABA (Australasian Bioplastics Association) there are approximately 150 Industrial Composting and Organics Recycling facilities in Australia. Some councils provide composting facilities through their kerbside waste collections via their green bin. However there are no state or national standards in terms of what they accept – some accept compostable packaging and some don’t.
Single-use plastic drinking straws, cutlery, plates, drink stirrers and cotton bud sticks made from conventional, degradable and compostable materials, are proposed to be banned. This will include compostable and landfill-biodegradable plastic versions of these items, however Biogone does not make any of these items, therefore the ban won’t affect our product range. We support the ban on single-use conventional plastics, however, home compostable and landfill-biodegradable plastic are still a more responsible choice for everyday other plastic items while being conscious of the environment.
Typically it is 12 months from the date of manufacture, depending on the product. To maximise shelf life the home compostable product should be stored in a cool, dry location free from moisture.
Compare the plastic technologies
|Plastic Property||Landfill-Biodegradable||Home Compostable||Compostable||Oxo-Degradable|
|Biodegradable in landfills?||Yes||Yes||No||No|
|Recyclable with other mainstream plastics?||Yes||No||No||No|
|Special storage conditions required?||No||Yes||Yes||Yes|
|Shelf life / has expiration dates?||No||Yes||Yes||Yes|
|Will degrade over a few months when exposed to sunlight||No||Marginally||Marginally||Yes|
|Fragments into small pieces in ambient air||No||No||No||Yes|
|Biodegradation begins at time of disposal; not before||Yes||Yes||Yes, in Commercial|
compost facility only
|Will biodegrade in commercial and home composts||No||Yes||No, Commercial|
compost facility only
|Needs oxygen in order to biodegrade||No||No||Yes||Yes|