The FAQ’s of Sustainable and ‘Eco-Friendly’ Packaging: Biodegradable and Compostable Packaging

The FAQ’s of Sustainable and ‘Eco-Friendly’ Packaging: Biodegradable and Compostable Packaging

What’s the difference?

Biodegradable is a loose term that has no defined time period for materials to break down, nor a defined quantity of materials left behind at the end of the degradation process. Compostable materials however have a defined time in which they must break down in order to be classed as compostable, and cannot leave behind more than a minute percentage of material. The speed of biodegradation depends on a range of factors including the original material and whether it ends up in an industrial composting facility, a backyard compost bin, or in the environment

What are they made from?

Bio-based plastics can either be entirely made from natural materials, like corn or wood pulp, or a mixture of bio-based and fossil-fuel based materials. Most biodegradable and compostable materials are not renewable; in fact, the Australasian Bioplastics Association (ABA) states that over 75% of bioplastics are bio-based, non-biodegradable materials. Currently in Australia, more bio-based plastics and even fully compostable plastics are ending up in landfill than actually being disposed of in an environment that allows them to compost. The expansion of composting infrastructure over the next few years will help curb this issue, as long as consumers are actively engaged and follow correct waste disposal behaviours.

Are they better than recyclables?

As a general rule, material recycling that aims to keep materials at their highest potential environmental value for as long as possible are preferable to using biodegradable/compostable materials, as renewable and reuseable materials are working towards the ideals of a circuar economy, unlike single-use compostable and biodegradable materials.

There are exceptions to this rule, however, where compostable packaging may achieve a higher value, for example:

  • Packaging heavily contaminated with food or another organic nutrients that cannot be easily removed by the consumer, and is therefore unsuitable for material recycling (such as takeaway food containers).
  • Packaging that could facilitate the recovery of waste organics, for example food waste bags or bin liners.

These applications for compostable materials will help curb food waste in landfill while reducing the contamination of recyclable materials through containment of organic material in a separate compostable container.

The long-term goal is for compostable packaging to be accepted in kerbside organics collections by the majority of councils, particularly where both food and garden organics are being collected for composting. However, this will take some time as only 18% of current Australian municipalities even provide organics collection at this time and there are less than 10 industrial composting facilities.

Who is policing claims associated with bio-plastics?

The Australasian Bioplastics Association (ABA) are the governing body overlooking domestic compostable material certification. While there are other standards around the world that cover commercial and home compostability, these are not equivalent to the Australian Standards, as they do not include the important test for ecotoxicity (the level at which packaging effects the earth during and after breaking down). If using compostable packaging, you must ensure your supplier has the correct certification.

Why can’t compostable/biodegradable materials be reused like recyclable materials?

The physical properties of compostable plastics are different to that of conventional plastics; the very nature of them is to break down, which dictates they are inherently weaker and highly susceptible to a variety of external factors. This is why compostable packaging has limited suitability, and their use must be assessed against performance requirements to determine their feasibility; there is no point using compostable or biodegradable packaging if the primary function of protecting/housing your product is compromised.

Issues that need to be considered include degradation by light, water resistance, susceptibility to microbial attack. Some compostable materials have a higher density and/or lower material strength than conventional polymers and may therefore use more material to fulfil the same function, which is increasing the resources needed to produce the packaging in the first place.