Plastic vs Compostable Packaging: Which Is Better for the Environment?

Plastic vs Compostable Packaging for Sustainable eCommerce Packaging. Main Image Source: Australia Post

While the global eCommerce industry has already seen exceptional growth over the last five years – almost tripling in size between 2014 and 2019 – the Coronavirus pandemic has sent things into overdrive. A recent report by Adobe found US online sales in May were up 77% from the year before, which accelerated eCommerce growth’ 4 to 6 years’.

But while this is terrific news for online retailers, the influx of order volumes has also led to higher shipping and delivery emissions – and a significant jump in the amount of eCommerce packaging.

With a global focus on sustainability, many eCommerce retailers have started moving away from traditional oil-based plastic packaging in favour of recycled, biodegradable, and even compostable alternatives – many of which are made from plant-based sources.

Unlike traditional plastics that can take 1,000 years or more to decompose, many ‘bioplastics’ claim to break down much faster or even completely – without leaving any nasty chemicals behind.

But while it seems like a no-brainer to create plastic from plants instead of oil, the rapid growth of bioplastic has raised many important questions about the sustainability, carbon emissions, and environmental impact of these ‘earth-friendly’ materials.

And as more types of sustainable eCommerce packaging enter the market, the general public remains largely unaware of the correct disposal methods – whether they be to use standard waste, curbside recycling, home compost, or the need for special facilities.

And so, with plastic vs compostable packaging, is it time to make a change to plant-based sustainable eCommerce packaging? Or are you better off sticking with plastic and focusing on recycling instead? Let’s take a closer look.

Plastic vs Compostable Packaging: Should We Choose Oil or Plants?

Whereas traditional plastics are derived from petroleum or gas, recent years have seen the emergence of ‘bioplastics’ made using plant extracts such as corn starch and sugarcane.

PLA – or polylactic acid – is the most common form of bioplastic and is found in many types of biodegradable and compostable packaging. PLA has provided a more natural alternative to traditional fossil-fuels and allows manufacturers to create packaging that decomposes back into nature – at least in theory.

As more and more consumers seek companies with sustainable credentials, we’ve seen an explosion of ‘green’, ‘eco-friendly’, and ‘natural’ sustainable eCommerce packaging – generally made from either biodegradable or compostable materials.

And while they sound like a perfect solution, it seems that most consumers – and indeed, many retailers – do not yet fully understand what these two terms mean, and what impact these materials actually have on the environment at large.

What’s the Difference Between Compostable and Biodegradable?

In basic terms, compostable and biodegradable plastics share the same core value: they are materials that can break down over time in a specific environment.

But when it comes to how they decompose, the timeframe needed to do so, and what they leave behind – the two materials differ significantly and this plays a significant role in the plastic vs compostable sustainable eCommerce packaging debate.

Compostable Plastics

Compostable plastics – when exposed to the right mixture of oxygen, moisture, and heat – break down into natural, non-toxic elements that promote healthy soil. While some compostable plastics can be placed in home compost, most require a high-temperature industrial facility to decompose successfully.

As compostable plastic breaks down, around 90% of it is converted back into CO2, leaving water and biomass as the remaining byproducts. For bioplastic to be officially certified as compostable, it must decompose at the same speed as organic matter, which is typically within 3-6 months.

Biodegradable Plastics

Biodegradable plastics can be either plant or oil-based, and contain additional micro-organisms that slowly break down the material into smaller and smaller pieces. It’s important to note that many biodegradable plastics are still made from petroleum, but with altered chemical properties.

Although biodegradable plastics can decompose, the resulting byproducts may contaminate soil and organic matter, and as such, they cannot be placed into compost. Instead, they generally require processing in specialised facilities, which sadly are not yet available in many areas. When disposed of in landfill, soil, or the ocean, biodegradable plastics generally decompose no faster than traditional plastic.

It’s also worth noting two crucial factors:

• Most bioplastic is not biodegradable. According to the Australasian Bioplastics Association, around 75% of bioplastic is non-biodegradable, despite being plant-based.
• There is no official degradation period for biodegradable plastic, leaving the term open to being used misleadingly.

Disposing of Biodegradable Plastics – A Complicated Affair

The terms’ biodegradable’ and ‘compostable’ often conjure up an image of material that quickly breaks down in virtually any setting – whether it be in a home or council compost bin, mixed in with regular waste, or even in water.

But as it turns out – that’s not exactly the case and is something often overlooked in the plastic vs compostable sustainable eCommerce packaging debate.

While biodegradable and compostable plastics do have the ability to break down completely – they also come with a list of important and often misunderstood caveats.

Compostable Packaging

Compostable packaging, for example, generally requires an industrial facility to heat the plastic to a high enough temperature for microbes to break it down, in combination with measured levels of oxygen and moisture. Home composting systems are unable to provide these conditions – meaning that most compostable packages will not break down in any useful timeframe.

When sent to landfill, compostable plastics are deprived of the light and oxygen needed to decompose, and can instead release significant levels of methane, a greenhouse gas 23 more potent than carbon dioxide. And when compostable packaging ends up in the ocean, the results are virtually the same as traditional oil-based plastics:

Biodegradable packaging

Biodegradable packaging, at least at this stage, does not have an effective end-of-life system in place. According to East Waste, a waste management authority in South Australia, “Biodegradable bags should only be used or placed into your general waste bin.”

Sadly, despite the promise of the name ‘biodegradable’, it appears that the only current method of disposal is to treat it the same as regular plastic and hope that it decomposes at a faster rate.

Plastic vs Compostable Packaging: Recycling or Decomposing- Which is Better?

As global eCommerce places an increasing focus on ‘green’ sustainable eCommerce packaging, there are also growing conversations around recycling, sustainability, and overall carbon footprints.

And so, to better understand the intricacies of our plastic vs compostable packaging analysis, let’s compare traditional plastic mailers with their plant-based alternatives:

Standard poly mailers

Standard poly mailers are generally made from polyethylene – the world’s most common plastic – and can only be recycled two or three times before the internal micro-polymers are damaged. While this degradation prevents them from being recycled into new mailers, they can still be re-fashioned into other solid items such as garbage bins, furniture, and plastic lumber.

Although recycling programs are gaining significant momentum around the world, the availability of facilities still varies dramatically between countries, cities, and even suburbs. Late last year, it was reported that Amazon’s plastic mailers were clogging up recycling machines in the US because local recycling plants did not have the ability to sort them correctly.

As we reported in a recent article, recycling plastic uses up to 88% less energy than producing plastic from virgin materials – but only around 9% of plastic is currently made from recycled materials.

Biodegradable and compostable mailers

Biodegradable and compostable mailers cannot be recycled, and should never be mixed in with standard plastic recycling. Due to their unique chemical structure, they can actually contaminate entire batches of waste during processing – resulting in large volumes of material being sent directly to landfill.

Instead, compostable packaging should be placed in curbside organic waste or composted at home, depending on the type of material. Biodegradable plastic cannot be composted, and must always be sent to a special facility or put in general waste.

If you wish to dispose of your bioplastic packaging correctly, you can ring your local waste management authority and ask about the disposal methods available in your area. There may be curbside collection options or local drop-off points that can process the waste and prevent it from entering landfill.

For eCommerce stores looking to adopt sustainable eCommerce packaging, we suggest that you research the materials carefully, work closely with your suppliers, and educate your customers about the correct disposal methods.

The Hidden Environmental Impacts of Plant-Based Plastics

While sustainable eCommerce packaging that decomposes seems like a perfect solution, we also need to consider the environmental impacts of creating – or rather, growing – the raw materials.

And many industry experts already view bioplastics as a counter-productive solution and therefore this weights heavy when it comes to plastic vs compostable packaging.

As compostable plastics are made using biomass – such as corn starch, wood pulp, sugar cane, and wheat straw – there’s a growing debate about whether creating high volumes of bioplastic is coming at the expense of our food supply. 

According to various studies, it takes approximately 2.5 kg of corn to produce one kilogram of PLA. And with global production of plastic hovering around 300 million tons per year, converting all of this into bioplastic would require 750 million tons of corn – almost double the USA’s entire annual yield.

There are also questions about the increased use of fertilisers, pesticides, GMO’s, and water – as well as the extra greenhouse gasses created by farming machinery. A 2010 study by the University of Pittsburgh found that bioplastics often created more harmful pollutants than petroleum equivalents, due to the farming and chemical processes needed to turn biomass into plastic.

From a carbon emissions perspective, bioplastics have the edge as the CO2 released during decomposition is equal to the carbon absorbed by the plants. In contrast, oil-based plastics gradually release CO2 that would have otherwise remained underground.

And perhaps most importantly, the study concluded that when plastics – either plant or oil-based – are created using renewable energy, carbon emissions can be reduced by 75% or more.

Plastic vs Compostable Packaging- Best Choice for eCommerce?

If you’re an online retailer looking to promote sustainability, plastic vs compostable packaging can be a difficult choice, and knowing whether to select traditional plastics or biodegradable materials.

Compostable and biodegradable packaging has many obvious benefits – but only when it is disposed of in a specific way. While the material can fully decompose under the right conditions, packaging suppliers and online retailers need to educate consumers about how to achieve this correctly. And as the popularity of bioplastic continues to grow, there are still many valid concerns about pollutants and land use that are yet to be adequately addressed.

On the other hand, there’s a reasonable case to be made for recycled plastic, which is made from existing materials and can be recycled again at the end of its lifespan. Provided the right systems are in place, recycled plastics will only continue to grow in popularity.

For any circular system to work – whether it be recycling or composting – it’s clear that we need greater transparency and a sharper focus on consumer education. Even though more and more people are trying to do the right thing with their packaging – the current disposal methods are confusing at best.

If you’re an online retailer and you’re sticking with traditional plastics, the best course is to use 100% recycled packaging – and encourage your customers to continue the process.

If you’re going down the biodegradable or compostable path, it appears that compostable plastic has the advantage, as most consumers have access to either home or curbside organic waste. While biodegradable plastic sounds appealing, it’s often no better for the environment – particularly when it ends up in landfill or the ocean.

But most importantly, we should all focus on minimising waste. Regardless of how ‘green’ our packaging might be – the most environmentally-friendly materials are the ones we don’t use in the first place.

Further Reading: Plastic vs Cardboard Packaging: A Complex Choice. Read More