The War on Plastic
Written by David Jackson
Earlier this year, The Netherlands was hailed as the home of the first ever plastic-free supermarket aisle: home to over 700 products free of synthetic plastic.
At the time, Sian Sutherland – co-founder of campaigning group ‘A Plastic Planet’ – stated: “There is absolutely no logic in wrapping something as fleeting as food in something as indestructible as plastic. Plastic food and drink packaging remains useful for a matter of days yet remains a destructive presence on the Earth for centuries afterwards.”
We have all seen images of the devastation caused to ecosystems by waste plastic. The evidence overwhelmingly indicates that plastic waste represents a threat to marine biodiversity. As with many aspects of modern life, we are well overdue to make some big changes.
I have spent most of my career publishing books aimed at helping plastics engineers to develop new plastic materials and products. These publications covered a wide range of topics: from hip replacements and drug delivery, to car body parts, helmets that reduce brain trauma and – of course – packaging designed to make food last longer.
If we want to continue seeing developments in these sorts of applications, plastics are going to be increasingly essential. The replacement of metal with plastic in vehicles increases comfort, safety, and fuel economy. The use of polymeric materials like UHMWPE and PEEK in orthopaedic implants is much safer than traditional metal implants. The invention of the plastic disposable syringe removed many of the risks of infection that came with the glass syringes they replaced – particularly for countries in the developing world.
However, it is in more consumer-oriented applications, such as packaging and food (particularly single-use), where plastics are increasingly considered controversial. This area is of legitimate concern and requires some attention.
As Eric Larson, plastics engineer and author, neatly puts it: ‘The word plastic is often synonymous with fake – plastic flowers, plastic people, plastic surgery’. We think of plastic and our thoughts turn to grocery bags, drinking straws, and water bottles. Examples of bananas individually wrapped in cling film suggest we have an addiction to plastic – a worrying combination of profit-maximisation by business and complacency on the part of consumers leading to an inexorable rise in plastic consumption and waste.
The challenges of plastics overuse stem from the very things that led to its widespread adoption. Plastics like polyethylene, polypropylene, polystyrene and PVC (so-called commodity plastics) are relatively cheap, durable, light, and easy to work with. They’re ideal for replacing traditional materials (like metal, glass and paper) in a range of products and enable the development of entirely new capabilities: new shapes, designs and colours, or embedded electronics, sensors and self-repair technologies.
It’s no surprise that plastics are big business: the industry directly employs more than 1.5 million people in Europe alone. Plastic has been used for anything and everything – and not always successfully or appropriately.
Considering what we know of the impact waste plastic has on our environment, it seems logical to do what we can to reduce plastics consumption. Many businesses are getting on board with this as well: several food and drinks outlets have swapped out plastic for paper straws and are offering rewards to customers who reuse cups.
Perhaps the most prominent example in the UK to date came in 2015, when the Government mandated a 5p charge for plastic bags in supermarkets. This reportedly reduced uptake of plastic bags by 86% and contributed to a 30% reduction in the number of plastic bags found on the seabed around Britain.
While these are clearly fantastic results, a recent study highlights another – unseen – side to the carrier bag sustainability equation. In early 2018, the Danish Environmental Protection Agency published the results of an investigation designed to identify the best material to use in grocery carrier bags.
Using a Life Cycle Assessment methodology (designed to take into account the environmental impact of production, use and disposal of the bags being tested), the researchers compared a wide range of bags, from basic low-density polyethylene carrier bags (i.e. the thin plastic bags that were previously ubiquitous in supermarkets) to biopolymers, paper, and organic cotton.
The report indicated that, assuming that a plastic bag would be reused once more as a waste bin bag and then incinerated, it was the best option in terms of sustainability – in some cases by a vast distance. The report calculated that a cotton bag (such as a tote bag) would need to be used thousands of times in order to have the same environmental impact as a plastic bag, as cotton requires vast amounts of resources to produce (in terms of fertiliser, water/land use and fuel for transportation).
The challenge comes in that we live in a complex system and focusing on one alleviating issue might cause negative impacts elsewhere. If your principal concern is for marine plastics debris then you are better off using paper bags, as these will degrade quickly. However, this could come at the cost of a bigger carbon footprint than plastic equivalents – and may still contribute to landfill waste. By the Danish team’s calculations, you would need to use a paper bag 43 times to match the performance of a plastic alternative.
The broader point is that all waste is bad. The effect of the grocery bag taxes should be to promote reuse and reduce overall waste, not to drive up sales (and waste) of other, less sustainable bags. Otherwise we risk trading one unsustainable practice for another.
Single and shrink-wrapped
We face similar trade-offs when it comes to food packaging. The sight of a shrink-wrapped cucumber might be a source of horror to shoppers but there is no doubt that plastic films play a critical role in keeping food fresh and edible for longer periods of time.
The magnitude of our food waste problem cannot be overstated: it is estimated that we throw away a third of all the food we grow. In addition to the waste of the resources used to grow, process, transport, and replace that food, we must also consider the greenhouse gases emitted by that food once it goes into landfill. The United Nations estimates that if food waste were a country, it would be the third biggest emitter of greenhouse gases in the world. In 2009, US food waste was estimated to account for 25% of that country’s freshwater use, along with 4% of its oil consumption.
The numbers indicate that, even in consumer products as fast-moving as food, plastics can have a beneficial impact in reducing waste. To wrap a cucumber in plastic film requires less than one gram of material, but the result is that whereas ‘an unwrapped cucumber may lose three and a half
percent of its weight after just three days, a plastic-wrapped cucumber may lose only one and a half percent of its weight over two full weeks’ – potentially the difference between the cucumber being eaten or sent to landfill.
This effect is seen across a range of different foods, with a staggering potential for extending the life of food. The resource requirements of food – and in particular, meat – typically dwarf the resource requirements of the packaging it is wrapped in.
According to Jane Bickerstaffe, Director of the Industry Council for Research on Packaging and the Environment: “Ten times more resources are used to make and distribute food than are used to make the packaging to protect it."
Given the energy expended simply to grow our food in the first place, there is a strong argument that using plastic packaging to keep it from being wasted serves the greater good, particularly when we consider the humanitarian impact. In many parts of the world, plastic is possibly the only material that can be used to safely deliver food to those who need it.
Seeking out a middle ground
The key is that – if we want to be meaningfully sustainable – we need to think holistically about all of our materials and activities. Scientists have estimated that 46% of the so-called Great Pacific Garbage Patch consists of discarded fishing nets and that the majority of the rest is composed of other fishing industry gear (such as ropes, eel traps, crates and baskets). A significant amount of this can be traced back to the 2011 Japanese tsunami. I mention these numbers not to try and exonerate plastics in food packaging (or indeed to put the blame solely on the fishing industry), but to illustrate the need for a more data-driven approach if we are to make meaningful progress on the problems we face.
Unfortunately, the development of biodegradable plastics is not a panacea, either. These are missing many of the benefits that make conventional plastics worth using (such as durability).
They risk confusing people over what should be recycled and what should be composted – something which is very likely to lead to more littering, not less.
Additionally, the full life cycle of biodegradable plastics can actually be quite wasteful. Plastics are a complex material that require a non-negligible amount of energy and resource to produce. If we compost these materials, this energy is effectively wasted.
Biodegradable plastics are great for a specific subset of applications, such as drug delivery or agriculture, but they are not the answer for all of our plastic-related solutions – particularly with the available technology and society’s expectations in terms of performance.
Invented for sustainability
Ironically, the first ever synthetic plastic was developed to provide a sustainability solution. Ivory was once ubiquitous in applications as diverse as cutlery, piano keys and billiard balls. Indeed, the decimation of the elephant population – and the commensurate rise in the price of ivory – led to pool table manufacturer Phelan and Collender offering a $10,000 prize to anybody who could design a viable alternative material.
In 1907, Belgian-American chemist Leo Baekeland invented Bakelite – a material now iconic for its use in retro telephones, TV and radio sets – and saved a lot of elephants in the process.
I don’t think that plastics are this generation’s ivory. Of course, plastics do not have the same direct and horrific impact as the ivory trade. Plastics also add functionality that we cannot currently get from other materials and – when deployed effectively – are as much a part of the solution as the problem.
Yet we still have a long way to go and changes must be made at all stages of the product life cycle. End-of-life considerations should be a fundamental part of the design and specification process, both in terms of the materials used and how they interact with each other.
Products should incorporate plastics into their design in a considerate fashion: avoiding or reducing their use when possible and ideally finding alternatives to non-recyclable materials. An example of a failure in this area was seen recently: UK local councils found that only a third of the supposedly ‘recyclable’ plastic it collected could actually be recycled, due to the way the products had been designed.
At the same time, particularly for products where consumers are responsible for waste disposal (such as sorting recycling in your kitchen), separation and disposal needs to be intuitive. Both local and national government should explore how they can improve the economics of plastics recycling.
In addition to lower oil prices making it cheaper to use 'virgin' plastic as opposed to recycled, recycling companies also suffer significantly when plastic recycling streams are contaminated with other waste. Contamination doesn’t just waste one bin’s worth of recycling: it can make a recycling business completely unviable. The more of our own waste that we can recycle here (rather than sending it to China), the better.
As consumers, we should continue to put pressure onto companies and governments to take sustainability seriously – not just cosmetically – by embracing sustainability as a core mission. The risk is that policy will be written with the intention of giving the illusion of doing something. It’s easier to go after drinking straws (which represent a very small fraction of waste) than the fishing industry or Chinese manufacturers – but the latter must also be done if we’re going to get plastic waste under control.
Finally, we could all go a little easier on ourselves for using plastic. It’s not just there because it’s cheap. Even in single-use applications, it often has its place. As a society, we should be trying to reduce all types of waste. Singling out one material for opprobrium (and not acknowledging its role in the wider solution) risks reducing our options when we need as many as we can get in the pursuit of a more sustainable world.