Plastic Bags: What Is the Difference Between Degradable and Biodegradable Waste

Fruit PackagingThe question sounds simple until you delve into it. Then you find it’s a minefield of marketing versus science, terminology versus clarity and drilling down into the subject seems to take you into an Alice in Wonderland plastic waste rabbit hole. The quick answer would be that a plastic bag is degradable if it breaks down in a landfill, industrial compost facility or a bin at home.

Biodegradable plastic bags should break down the same way or one would imagine, faster.  The problem is in the terminology. While everyone wants to help minimise waste and clean up our environment, to do this we need to either ban plastic altogether or use certifiable compostable or so-called biodegradable packaging properly and label them appropriately to avoid confusion so that the right plastic goes to the right place from home garbage, recycling bins and businesses

The following information should help to clarify the issue. 

What is a Degradable Plastic Bag?

Fruit Bag Who knows? Plastic can take hundreds of years or more to degrade so all plastic is degradable. It depends on how long it takes and the damage it does in the environment in the meantime. But some manufacturers are using additives or making bags from cornstarch and other organic materials that either degrade over a few years in landfill or in some cases are marketed as home compostable.  But according to (1) the Federal Government’s Australian Packaging Covenant Organisation (APCO), there is no widely recognised identification or labelling system in this country to identify and properly dispose of degradable, biodegradable or compostable plastic bags or packaging.

This leaves environmental conscious consumers understandably confused and frustrated about the difference between a degradable plastic bag and a biodegradable one. The only recognised labelling system is the Australasian Bioplastics Association (ABA) (2) which issues licenced logos providing evidence of compostability certification through its voluntary though strict verification program. 

Okay, So What is a Biodegradable Plastic Bag?

Biodegradable Bag For a start, ‘biodegradable’ means material that decomposes through the actions of microorganisms such as fungi or bacteria and produces a more environmentally-friendly end product or soil. Some biodegradable plastic is different to other degradable plastics because it won’t biodegrade unless exposed to a microbe-rich landfill, unlike traditional plastic which takes hundreds of years as mentioned above. Then there’s the problem of bags degrading into small particles or micro particles of plastic that end up in the food chain and onto our plates. APCO is concerned by the use of the word ‘biodegradable’ since it is often misused and applied in marketing to a wide range of different materials.

Biodegradable as a term is unclear, since a  so-called ‘biodegradable’ product might not biodegrade in some environments and will in others and in vastly different periods.  However, all certified compostable plastics should biodegrade, and if they’re mixed in a composting environment they should end up as soil. The trouble is, not all biodegradable plastic will become compost. Since natural water and soil areas aren’t controlled, the time frame for biodegradation varies considerably.

This means the term ‘biodegradable’ should be avoided in packaging because it implies all biodegradable materials will behave the same way when disposed of, which is far from the case in reality. 

Compostable Plastic Bags

Compost BinNot all bio-based plastics are compostable or will biodegrade. For a plastic to be sold as ‘compostable’ it has to be certified to the Australian Industrial Composting Standard – AS 4736: 2006. However, Australia has no consistent organics recycling system, which makes it impossible to get the right message across to consumers about the correct way to dispose of what is marketed as compostable plastic bags and packaging.

Disposal methods differ from state to state and council to council. Compostable plastic packaging is manufactured as suitable and certified for composting but it can’t be mixed with traditional plastics for mechanical recycling since it can contaminate the machines. Phasing out plastic bags and packaging seems the only solution.

Federal Government Tackles Plastic Waste

Handshake In March this year (2021), the Federal Government announced it will take the battle against plastic waste up a notch from beaches free of plastic, to ending the confusion over household collection systems. When launching the National Plastics Plan, Environment Minister Sussan Ley said Australia must now change how it produces and consumes plastics.  The Minister told reporters that Australians consumed one million tonnes of single-use plastic every year, from plastic bottles to polystyrene packaging and plastic consumer goods.

This is creating mountains of pain for the environment and wasting potential assets, she said. The Government plan includes five key areas: community education, investment, legislation, research and development and industry targets including new labelling guidelines, and an end to polystyrene food and beverage containers and filling for packaging.




Author’s Bio Alex MorrisonAlex Morrison has worked with a range of businesses giving him an in-depth understanding of many different industries including financial management, home improvement and biodegradable garbage bags. When he’s not in scheduled meetings or leading his marketing team with client work, Alex spends his time with his family including his two young kids – playing sports, having a family bbq, and more.

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