The terms “compostable” and “biodegradable” are often used interchangeably, but they do not mean the same thing.
The simplest explanation is: certified compostable products are biodegradable under defined composting conditions, but biodegradable products are not necessarily certified compostable.
Understanding the difference can help Australian households and businesses avoid misleading environmental claims and choose products with a clearly defined end-of-life pathway.
What Does Biodegradable Mean?
A biodegradable material can be broken down by microorganisms over time. However, the term alone does not tell you:
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How long the material will take to break down
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What conditions are required
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Whether it will break down completely
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Whether it may leave microplastics or unwanted residue
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Which waste stream should be used
A product labelled only as “biodegradable” may still take years to decompose, particularly if it is placed in landfill or an unsuitable environment.
What Does Compostable Mean?
A compostable product is designed to break down under specific composting conditions into materials such as water, carbon dioxide and biomass.
Certified compostable products must meet defined requirements for biodegradation, disintegration and environmental safety. This provides more certainty than broad claims such as “eco-friendly”, “green” or “biodegradable”.
Compostable vs Biodegradable: Quick Comparison
| Feature | Biodegradable | Certified Compostable |
|---|---|---|
| Breaks down over time | Yes, under certain conditions | Yes, under specified composting conditions |
| Defined timeframe | Not necessarily | Required by the relevant standard |
| Independently tested | Not always | Yes |
| Environmental safety testing | Not guaranteed | Required by recognised standards |
| Clear disposal method | Often unclear | Home or commercial composting, depending on certification |
Australian Compostability Standards
In Australia, there are two important compostability standards:
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AS 5810: Products suitable for home composting
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AS 4736: Products suitable for commercial or industrial composting
Products independently verified by the Australasian Bioplastics Association may display the appropriate certification logo.
A home-compostable product can break down under the lower-temperature conditions found in a correctly maintained household compost system. An industrially compostable product generally requires the controlled conditions and higher temperatures of a commercial composting facility.
Why Certification Matters
Certification gives consumers and businesses greater confidence that a product has been tested against recognised requirements.
When choosing compostable products, look for:
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A recognised Australian compostability certification
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The relevant standard number
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Clear disposal instructions
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Information about whether the product is home or commercially compostable
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Specific claims rather than vague environmental language
Choosing Compostable Everyday Products
Replacing conventional plastic can be practical when a disposable product is genuinely needed.
Bonnie Bio offers certified compostable products for Australian homes and businesses, including:
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Compostable straws and food-service products
These products provide alternatives for everyday applications where conventional plastic is commonly used.
How Should Compostable Products Be Disposed Of?
Always follow the certification and disposal instructions provided with the product.
Products certified to AS 5810 may be suitable for a properly maintained home compost system. Products certified only to AS 4736 require an appropriate commercial composting facility.
Council and FOGO acceptance varies across Australia. A compostability certification does not automatically mean that every council green bin will accept the product, so check with your local council or waste provider before disposal.
Compostable products should not normally be placed in standard plastic recycling bins because they are made for composting rather than conventional plastic recycling.
Make More Informed Sustainable Choices
Choosing certified compostable products can help reduce reliance on conventional plastic when supported by the correct disposal system.
The key is to look beyond vague claims. Check the certification, understand the required composting conditions and confirm that you have access to an appropriate disposal pathway.
Explore Bonnie Bio’s range of certified compostable products for practical alternatives to conventional plastic.
Frequently Asked Questions
Is compostable the same as biodegradable?
No. Certified compostable products must meet defined compostability requirements. A product described only as biodegradable may not have a specified breakdown timeframe or disposal pathway.
Is every compostable product suitable for home composting?
No. Look for AS 5810 certification for home compostability. Products certified only to AS 4736 require commercial composting conditions.
Can compostable products go in a green or FOGO bin?
Only if your local council or waste provider accepts them. Requirements vary between Australian councils and composting facilities.
Can compostable plastic go in a recycling bin?
Generally, no. Compostable products can contaminate conventional plastic recycling streams. Follow the product instructions and local waste guidance.
Do compostable products break down in landfill?
Landfills usually lack the oxygen and controlled conditions required for effective composting. Certified compostable products should be directed to their intended composting pathway whenever possible.
