Plastic, Bioplastic or Compostable Plastic? Here’s How to Make The Most Sustainable Choice

Image: Dr Imogen Napper

Plastic has earned itself a bad reputation, but are some of the available alternatives doing more harm than good? From bioplastics to alternatives such as cardbard and glass, Flora Beverley and sustainability research assistant Hattie Webb look at the advantages and drawbacks to find the most planet-friendly packaging available.

It is estimated that people in the UK use 5m tonnes of plastic every year, around half of which is single-use packaging. This is only set to grow, and at our current trajectory we are set to have more plastic than fish in the ocean by 2050 – a fact that every eco warrior has heard, despite it being provenly difficult to calculate

In an effort to reduce environmental impact (and cater to an increasing amount of sustainability-conscious customers), many supermarkets and businesses have started to reduce their plastic consumption. Iceland has pledged that its own-brand items will be plastic-packaging free by 2023. Tesco, which has set its target at 2025, has reduced the amount of plastic in some of its packaging – including meat trays – and made supportive noises about the much-mooted depositreturn scheme. Even single use water bottles, once widespread at events, are now starting to be replaced. The London Marathon offered runners seaweed pouches at some of the aid stations, reducing the need for so many plastic bottles. All of this is in response to the 2018 European Parliament vote to introduce a ban on single-use plastic items by 2021 in a bid to limit future environmental damage.

Banning plastics, however, introduces the need for replacements. The use of ‘alternative plastics’ has since exploded, with ‘bioplastic’ production set to quadruple between 2016 and 2021. The use of these alternative plastics are being adopted by many food and drink companies, but are the alternatives always better?

The environmental thinktank Green Alliance suggested there was evidence that by using terms such as ‘biodegradable’, customers were more likely to discard items into the environment, making pollution on land and at sea even worse. But what is the problem with these alternatives, and how can we responsibly consume without making the issue worse?

There are lots of varieties of alternative plastic, with more being made each day. There are two key labels – bioplastic and compostable – that many put on their packaging as evidence of their ‘greener’ nature. But is this really the case?

Image: Vegware

The alternatives

Let’s start with bioplastics. Bioplastics are a diverse group of materials, and the term has several meanings. They can be made using polymers derived from plant-based sources such as starch, oils, cellulose etc. Bio-based polymers can also be used to create non-biodegradable plastics that behave in exactly the same way as conventional plastics, so just because ‘bio’ is in the name does not mean it is biodegradable. Coca Cola’s PlantBottle, for example, though partly derived from sugarcane is chemically identical to hard-to-breakdown polyethylene terephthalate (PET) bottles. So, it can be recycled many times but it won’t break down for centuries. Equally, the term bioplastic can refer to plastics created from fossil fuels which are made to be biodegradable (as neatly explained in the diagram below from WRAP). The term is used for a wide range of materials that do not necessarily all behave in the same way. 

Then we have compostable plastics. There is an industry standard that plastics must meet to be deemed ‘compostable,’ which ensures they can be decomposed/biodegraded in industrial composting conditions. Not all biodegradable plastics are compostable, but all compostable plastics are biodegradable, in the right conditions. What this does not mean is that they can be placed in household composting – these products must be specifically labelled as such.

Image: WRAP

The problem 

There is currently a lot of confusion among the general population of what the above terms mean, and how to safely and sustainably dispose of these items. Unfortunately, if biodegradable and compostable plastics find their way to the wrong bins and wrong sorting facilities, they are no better than conventional plastic and often worse. Much of the compostable packaging produced for the UK market only degrades in industrial composting facilities, rather than in home composting – but not all is sent to these facilities, so instead sits in landfill or marine systems behaving in the same way as our problematic conventional plastics. 

Any plastic that evades appropriate collection and treatment systems and instead makes its way into the environment has the potential to have long-lasting negative impacts. Jo Ruxton, cofounder of Plastic Oceans, shares that even biodegradable plastics can take years to break down at sea. “They can be mistaken for food and ingested, they can entangle animals. They can do everything that plastic does – they just don’t last as long.”

Currently, biodegradable plastics cannot be recycled in the same way as conventional plastics and must be separated and dealt with on their own. Similarly, compostable plastics must be composted in industrial conditions, and should not be placed in the recycling bin. Vegware, a compostable packaging manufacturer, said it advised consumers to put their products in the general waste if suitable composting was not possible.

As such, these ‘alternative plastics’ are often best limited to closed environments, such as universities and hospitals, which can help the packaging make its way to the correct facilities. Otherwise, it is unclear whether they are significantly better than conventional, recyclable plastic. 

“If we aren’t careful, short term decisions could cause longer term problems for establishing a true circular economy,” explains Adam Read, external affairs director at SUEZ recycling and recovery UK, to Green Alliance. “As the war on plastics continues to rage, avoiding unintended consequences should be at the forefront of everyone’s minds, and that includes government, industry and, of course, consumers. Change must be managed and planned if we’re to move towards fully closed-loop systems for recycling and, more importantly, reuse.”

“That means we need to think much more carefully (and quickly) about how materials like compostable plastic are introduced. We must ensure a system where they are used where they make sense and in a way that people will understand to limit contamination and leakage.”

Image: Plastic Oceans

When plastic may be the best option

There are still times when plastic, as opposed to alternatives such as wood, metals and glass is the best option we currently have. This is due to its versatility and inertness as a substance. One occasion in which plastic still may be the most planet-friendly choice comes down to the fact that it weighs less than alternatives, reducing emissions during transportation. While there are calls for items to be stored and transported in glass or metal containers instead of plastic, these are both significantly heavier and can still contribute to landfill/marine waste in the same way as plastic (as well as being energy intensive to make). The added weight increases carbon emissions during transport, often negating potential benefits of switching material. 

Another case where plastic may really be too good to go in for extending the shelf-life of food products. Food waste is a huge contributor to carbon emissions, with around 30% of food produced for human consumption being discarded each year (UN). If food waste was a country, it would be the third highest carbon emitter in the world. Plastic packaging can protect food and prolong its life, helping reduce wastage and in turn, lowering carbon emissions. 

Lastly, plastic is still the best option for storing products such as bleach and medicines, since it’s a non-reactive, water and air-tight container. Metals and glasses certainly have their uses, but are not suitable for all modern-day applications.

The solution 

It is clear that banning all conventional plastics will not solve our environmental problem. Since issues arise when plastic ends up in our oceans and landfill, the age-old saying of ‘reduce, reuse, recycle’ (preferably in that order) is the best method of limiting the problem. 

Start by reducing the amount of unnecessary single-use plastic you use in your life. Opting for reusable alternatives not only saves resources, but also may save you money. Buy recycled plastics where possible – these have a far lower environmental impact and limit the use of virgin plastics.

Reuse plastic you already have. Rather than purchasing tote bags, paper bags or new containers, reuse your existing plastic bags/containers as much as possible. Make sure every piece of plastic you get has the longest life out of the bin as possible. Our issue is not so much that we don’t have the materials we need for sustainable systems, but that we have a single use, disposable economy. We need to start to reuse items, call for more refillables, and fix products that are broken. Anything to keep products out of our waste systems.

When you finally have to throw plastic out, make sure to recycle it. Household recycling rates in Britain are around 46% (2017), with only 31% of plastics estimated to be recycled in 2018 (as opposed to incinerated or ending up in landfill). Recycling rates are thankfully improving, but need all the help they can get. If you have unavoidable plastic waste, make sure to recycle it properly. Recycling plastic significantly reduces the need for new plastic to be made which positively benefits our environment. 

It is clear that there is no simple one-size-fits-all solution to our plastic problem. There are times when it is evident that for such an environmentally costly material, plastic is being used in the wrong way, and businesses should look for alternatives where appropriate. There are a multitude of factors to take into account, from the energy demands of creating a material, to the uses and benefits it might have during its life, to its disposal after that life is up. There is no simple solution, except to use less.

Alternative plastics won’t ‘cure’ our belief that once we dispose of an item it simply disappears, and it is possible that they may in fact perpetuate the disposable culture at the root of the crisis we’re currently seeing. We need to better understand how to sort our own domestic plastic before blindly switching to alternatives, and consider how much we really need a constant supply of disposable items at all.