Does your rubbish really need to be put in a plastic bag?

We're answering your toughest sustainability questions! Ask us via Facebook, Twitter or email - #Ask1MW. This week, we've been asked…

Do biodegradable rubbish bags work? And what are the alternatives?

The abovementioned bin liner dilemma crops up a lot. If you've been wondering this same question, you're not alone.

It'd be wonderful if biodegradable plastic products such as rubbish bags were a solution for reducing plastic waste pollution, but they don't work effectively enough yet.

What does biodegradable mean?

Something is considered biodegradable if it can be broken down by living things, usually by microorganisms like bacteria and fungi. Unfortunately, when it comes to plastic garbage bags it's not that simple.

[Image: Shutterstock]

Choice says:

"There are certain conditions, like temperature and moisture, which affect how well a plastic breaks down. This means a biodegradable plastic will not simply break down wherever it ends up. If it is not disposed of correctly or ends up as litter, it might not break down at all.

In Australia, the term biodegradable usually refers to plastics that are 'compostable', meaning they will break down when placed in a home compost bin or commercial composting facility. When disposed of correctly, a compostable plastic will almost completely biodegrade within six months – a big improvement on the 100-plus years it would take for something like a normal plastic bag to break down in a landfill."

This is why biodegradable plastics are not effective yet because they must be disposed of correctly or they may never break down as claimed. Furthermore, disposing of them correctly is harder than you'd think. In Australia, for example, "the majority of products currently available are labelled 'compostable', meaning they need to go to a commercial composting facility."

Rowan Williams, president of the Australasian Bioplastics Association, told Choice there are only around 150 of these facilities in Australia, but not many of them are in the major cities.

"If you've got the place for these plastics to go then it works beautifully, but today in mainstream Australia there is no guarantee that a compostable plastic will go to a composting site because they are not that prevalent,"
- Williams said.

To be sure your biodegradable/compostable bags end up in the right place, you need to check with your local council on what composting facilities are accessible through their kerbside waste collections.

[Image: Shutterstock]

Degradable is not the same at biodegradable

The other label you might have seen on plastic products is 'degradable.' Please note 'degradable' is not the same as 'biodegradable.'

Degradable products do not require living organisms to break down. Instead, chemical additives are used in the plastic to make it crumble more quickly into smaller pieces of plastic than it would otherwise. Thus, the plastic pollution problem is still there if not worsened as smaller pieces of plastic litter can be more hazardous to wildlife.

Too many labels

With so many different labels bandied about including biodegradable, compostable, degradable; how is a consumer to know what is what?

Choice has put together this fabulous guide to help you know what terms to look out for:

  • Biodegradable will biodegrade, but generally not as quickly as compostable plastic. Look for products that state they are 100% biodegradable and show the disposal method.
  • Compostable will biodegrade in a commercial compost facility. Look for the Australian Standard number (AS 4736-2006) on the label.
  • Home compostable is the best option if you have a home compost bin. Look for the Australian Standard number (AS 5810-2010) on the label.

But watch out for these:

  • Bio-or plant-based means the plastic is made from plant materials rather than fossil fuels, but this doesn't necessarily mean it is biodegradable or compostable.
  • Bioplastic is a confusing industry term that has two meanings – it could mean the plastic is biodegradable/compostable or that it is made from plant materials. Ignore this term, as it's not reliable.
  • Degradable is neither biodegradable nor compostable.

What are the alternatives?

Now is a good time to look at the second part of this question on alternatives. There are two main alternatives to bin liners we want to cover:

  • Not using a bin liner
  • And newspaper

[Image: The Alternative]

Abandoning a bin liner may or may not work for your household. You might feel comfortable with this option if you don't produce much waste by recycling and composting everything you can. Simply empty the waste from the household bin into your wheelie bin for collection.

Please consider you might have to wash your bins more often, and that odour and vermin might be a concern depending on what you're throwing away. Additionally, some communities don't have wheelie bins or still use manual garbage collection, in which case unlined garbage could be inappropriate and even a hazard.

Wrapping waste with newspaper is another solution if you don't feel comfortable using no lining, but some of the considerations above will still apply.

To conclude: Reduce your waste

There you have it. Biodegradable plastics can be effective if used and disposed of correctly. Unlined or newspaper-lined bins can work if you produce little waste to begin with.

Finally, the best solution of all is to reduce your household's waste by refusing, reducing, reusing, repurposing, and recycling.

[Header Image: Shutterstock]

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