Eco friendly catering & packaging supplies, Eco-lifestyle products & Natural Home-wares

Degradable, biodegradable & compostable

Compostable plastic

Degradable, bio-degradable and compostable - are you bamboozled?

Are you trying to make more eco-friendly choices when you buy, but so confused by all the terminology that is thrown about to try to convince you something is 'green'? You are not alone - even the people using these terms often don't really understand what they mean.

We're here to help! We hope that by sharing an understanding of what these things mean, we'll be able to inspire people in every home and organisation to make sustainable and eco-friendly product choices without the confusion!

Degradable bag

Degradable is a broad term given to natural and man-made substances that can be broken down by natural processes into smaller parts. Basically everything is degradable!

Things can be photodegradable (broken down by ultraviolet light), oxodegradable (broken down by thermal exposure) or biodegradable (broken down by the action of microorganisms).

The term ‘degradable’ in itself does not specify any time frame in which something will break down…for instance, old paintings are displayed under dim lighting to reduce the effects of photo-degradation, which could take place over years. A large tree trunk might take a century to biodegrade. A tin can is degradable too; it will break down over a long period of time through oxidation, and weathering. An Oxo-degradable plastic bag (regular plastic that has been treated to make it degradable), will begin to degrade after about 12-18 months, and the time it takes will depend on how much light and stress (movement) it experiences. But it is still made from a non-renewable resource, and could stay in the environment for many years.

Biodegradable bag

Biodegradable is a term given to material that, as a result the of biological activity of microorganisms (bacteria, fungi and algi), breaks down completely into the raw materials of nature (CO2 , H2O, inorganic compounds and biomass) from which it was made, and disappears into the environment. Just like the term 'degradable', biodegradable does not give any indication of time frame so the process could take years - for example, the straw in a straw-bale building will biodegrade over many years, if not maintained. The good thing is that if something is certified biodegradable, you know that the end result is going to be the raw materials of nature.

Compostable bag

Compostable is a specific term given to biodegradable materials that biodegrade within in a certain time frame under typical composting conditions. Different countries have different standards by which they certify compostabiliy of a product, but they are all based around whether a material can break down into the materials of nature within the typical commercial composting cycle of about 8 weeks, with high heat and movement of the pile. Australian compostability standards go one step further - to be certified, a material must be proven to have no detrimental effect to worms or microorganisms in it's end state (after composting).

An important thing to note about products that are certified compostable, is that this is based on commercial composting. Home compost systems are generally no match for commercial systems, in which piles are enormous, generate huge amounts of heat, and are turned daily. Home compost systems will be able to compost some types of compostable products (such as compostable bags), but not others (such as PLA cups - they really require heat to break them down).

Biodegradable, degradable compostable

So which is best? Degradable, biodegradable or compostable?

We believe that if possible, ‘compostable’ is always the best option, because it ensures that a material will break down to the materials of nature, in a short time frame.

However, like all decisions, the deciding factors will be how you are using something, and how you plan to dispose of it. If you are organising a large event, you ideal scenario will be that you choose compostable catering ware and work with a commercial composter to compost all food scraps and catering ware. This is the way of the future, and we believe it will one day be how ALL events are run.

Even if you are unable to compost, compostable products are still ex excellent choice because they will break down the fastest, and into the base materials of nature. Common 'compostable' items you can choose from are compostable rubbish bags, sugarcane plates, palm leaf plates, and Biocup coffee cups.

Our second choice would be biodegradable - because it turns back into natural materials eventually, even though it takes longer than a compostable product. Sometimes things might only take twice the time frame required to be certified compostable, but if you are home composting and have time, this might still be a good option. An example would be our wooden cutlery, which is too dense to be broken down in one composting cycle, but which will definitely turn back into the materials of nature given just a bit more time. Common 'biodegradable' items are wooden cutlery, PSM cutlery and wooden trays.

Personally, we don't like 'degradable' products. We think they are misleading and confuse people into thinking they are biodegradable and an eco-friendly choice (see the image of the degradable bag at the top of this blog). A degradable bag is simple an ordinary plastic bag made from a non-renewable resource (oil), which will only degrade into smaller pieces of plastic - what's so eco-friendly about that??

We hope this article has helped you navigate some tricky green terminology - post a comment or write to us if you have further queries or ideas :-)

By Lucinda Flynn of Going Green Solutions

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