The plastic challenge
James Beard discusses the issues surrounding plastic waste and outlines some potential solutions.
Across the globe plastic production is on the increase. In 2016 alone, up to 335 million tonnes was produced, which is is a doubling of output in just two decades! At current rates, global plastic production will be 2,000 million tonnes by 2050.
This is because plastic is a strong, lightweight, cheap and flexible material, which is used in the manufacture of a huge range of products. Many aspects of our day to day lives would not be possible without plastic.
The huge volumes of plastic, the wide range of things made from plastic, and the variety and combinations of polymers used can make plastic difficult to capture, correctly identify and recycle into useful items.
The challenge is how to utilise such a useful material in a way which minimises the impact on the environment when it reaches the end of its life. How can we make it easier to identify, recycle and capture the value of plastic in the economy rather than losing this resource in the form of litter, waste or ocean borne plastics or microplastics?
Plastic in the oceans
It is estimated that eight million tonnes of plastics enter the oceans each year!
We have all seen the devastating impact plastic can have on animals, habitats and places we never thought could be touched by plastic in such a damaging way. And this is from the large plastic pieces we can see. An additional concern is the smaller nano and microplastic fragments, which can pass into the edible tissue of fish and molluscs that we eat. This means that plastic is directly entering our food chain. No one yet knows the impact of this on the animals or us.
The problems we face are huge in scale and complex to resolve. How do we stop plastic entering the oceans? How do we clean up what is there already? What can we do to ensure we manage and protect our natural resources more carefully?
Why is plastic still being produced if it’s causing so many problems?
Plastic production is not inherently bad. There are very good reasons why it has become such a diverse and popular material. Plastics display many unique properties which are extremely hard to replicate. For example, they are lightweight, flexible, durable, easily coloured, recyclable, waterproof and relatively energy efficient to produce – by many measures plastics are more environmentally friendly than other materials.
However, something which displays such valuable properties should be treated as such – something valuable!
In a world where only 9% of plastic is recycled and over two billion people don’t have access to proper waste management, does it make sense that plastic is used in applications where its useful life is measured in seconds?
What are the alternatives?
A bewildering array of alternatives to traditional plastics exist. For example, bioplastics, biodegradable plastics and compostable materials; however, there are many pros and cons to these which I have outlined below. These need to be carefully evaluated before switches are made:
Bioplastics are chemically like normal plastics but are formed from renewable sources such as biomass. However, they generally behave in the same way at end of life as traditional plastics so, although they may use less energy to create than traditional plastics, are not a solution to marine or land litter.
Biodegradable plastics may sound like an ideal solution, but the reality is that they do not easily solve the plastics problem.
Biodegradable plastics are often designed to breakdown in industrial composters which apply heat. Without heat they don’t breakdown very quickly. This means that in normal circumstances such as in a hedge or in the sea degradation can be very slow, often many years or even decades.
Another issue is that multiple plastic types cause confusion, so introducing biodegradable plastics is likely to add to this. There is a risk that biodegradable plastics will contaminate recycling streams and that traditional plastics could contaminate composting streams, leaving neither waste stream suitable for recycling or recovery.
It is also important to understand what biodegrading means; if it is simply a case of breaking down in to micro-plastic fragments faster, then that is not a solution! There are also some question marks as to the long-term effects of additives which achieve this.
In the rush away from plastics we are seeing that paper-based products are in vogue. They are cheap, light, flexible and can be adapted to mimic some of the properties of plastic, but they are not a silver bullet.
Waterproofing is needed to make paper useful for many of the functions carried out by plastics but doing this makes the product difficult to recycle. They require additional pulping or additional chemicals and can contaminate normal paper streams.
Solutions do exist, but the following will require a lot of effort from individuals, government and industry:
- Avoidance of unnecessary plastic
- Mandatory labelling of polymer types
- Mandatory usage of biodegradable plastics in certain applications that will not contaminate recycling streams, such as bin bags
- Streamlining of polymer types used
- Standardised collections across regions
- Avoidance of plastic laminates that incorporate multiple polymer types
- Alternatives to carbon black pigments:
- These confuse sorting equipment, which is why many are calling for the removal of black plastics entirely
- However, with more and more companies signing up to The UK Plastic Pact, one of the targets of which requires 30% recycled content in packaging, black plastic is likely to be an important part of the solution as it can hide the colours of the recycled feedstock
- Investment in waste management infrastructure in high-leakage areas
- Creation of more effective economy for plastics, thus giving post-use plastics more value and keeping it in the system
The plastic waste problem is a truly global issue that will require global solutions. Paradoxically however, it is also a problem that almost everyone can help solve by making small changes to how they consume plastic and how they view it as a material.