Notes

WHY CAN'T ALL PLASTIC WASTE BE RECYCLED:
The UK produced 11m tonnes of plastic waste in 2017, and recycled around two thirds of it. Or so it seemed. A report by the National Audit Office (NAO) shows that over half of the UK’s recyclable waste is sent overseas for recycling, but much of it is likely to end up in landfill or the ocean instead.
The recycling regime is a mess in the UK - but what’s stopping Britain from making all of its plastic waste recyclable and ensuring it is actually recycled?
Public engagement has played a big part in tackling plastic waste in the environment. Reaction to scenes in Blue Planet 2 where marine wildlife struggled with plastic in the ocean prompted government action. The recent ban on microbeads in cosmetics and the 5p charge for plastic bags are positive steps, but these gestures are just a start.
Supermarkets have promised in a “Plastic Pact” to eliminate avoidable packaging and ensure all of it can be reused, recycled or composted by 2025. One third of supermarket plastic cannot easily be recycled at present, and while the pact among retailers is only voluntary, its target is welcome. That said, just because a plastic is recyclable does not guarantee that it will be recycled. Local kerbside collections vary from place to place and many authorities only accept limited types.
The barriers to recycling plastic waste
There is a huge range of different types of plastic used in disposable products and packaging. One solution is to limit the types of plastic to a single standard which is easy to recycle. This might mean fewer coloured plastics. Black food trays are a particularly troublesome example as they contain pigments that make packaging harder to detect by sorting technology.
Mixed materials are those that have different types of material in the same product. For instance, a plastic bag with a foil lining or a disposable coffee cup made of paper with a plastic lining. These are especially difficult and expensive to separate. They are considered in many cases contaminated and worthless.
Designing packaging so that it’s easier to separate is vital. Some consultancies offer advice to companies on how to achieve this, for instance, by having outer layers that are removable by the consumer and using water-soluble glues. This design-for-disposal approach would mean that food-grade plastic streams – materials which are safe to use in direct contact with food – are easier to identify and separate, increasing their availability and making them worth more as a material to put back into the cycle.

Mixed material waste (which includes some types of coffee cup) is currently difficult to separate and recycle.
The raw feed stocks for most plastics are fossil fuels, which are cheaper to use than recycled material. Plant-based feed stocks are a good lower-carbon alternative but are often in competition with crops used to produce energy or food and are not always as sustainable as they might appear. This is where government intervention can have a big impact. A levy on making new single-use plastic rather than using recycled material would create a level playing field and raise funds to subsidise the development of new, cleaner materials.
A plastic-free future?
Could we just get rid of all plastic packaging? Sadly, no. Some of it is considered unavoidable. Plastic prolongs the life of produce. It provides a barrier to bacteria, a film to lock in protective gas and a convenient waterproof layer. It would be difficult to imagine buying products like raw fish without it.
But there are solutions – consumers can take their own reusable containers to shops, and retailers can use more recycled (and recyclable) materials. 2025 is a long way off when plastics are in food chains now. Eliminating single-use materials is possible but it’s going to involve us all in the solution.
Businesses are talking about the issue but the public could be forgiven for impatience over the lack of choice and commitment. They need to innovate. The government, meanwhile, has made some positive changes but these have been easy wins so far. They need to provide funding and legislation which supports alternatives to single-use plastics. Consumers also need to be prepared for a little inconvenience. Plastics are not a disposable commodity, they last hundreds of years in our environment and until now their true lifecycle cost has not been reflected in the price at the till.

Plastics are incredibly useful materials with extremely diverse properties, allowing a multitude of different applications that benefit our lives.
Bottles and forks aside, in the medical field alone plastics have been used for artificial heart valves, medical implants and devices, controlled drug release, specialist surfaces and coatings that repel water, organic batteries – the list is endless.
But, with marine plastic debris estimated to reach 250m tonnes by 2025, governments across the globe are starting to think about how to overcome this significant problem.
A fundamental part of this issue is that non-sustainable, single-use plastics account for up to 40% of global plastic production. This equates to around 128m tonnes. The vast majority of these plastics have low recycling rates and do not biodegrade in an acceptable time span – polypropylene can take millennia to break down properly.
Worse still, if these plastics find their way into the marine environment, the motion of the sea along with sunlight can cause the plastics to fracture into small particulates called “microplastics”.
The presence of macro and microplastics in our oceans has been shown to have a detrimental effect on marine life. But the potential effect on human health is much less well understood.
A ban on the production of cosmetics and personal care products containing plastic microbeads came into effect at the beginning of the year. Though realistically, this only accounts for an estimated 680 tonnes of microplastics per year in the UK.
The problem with plastics
It is clear then that plastic waste is a complicated problem – spanning economics, sustainability, social pressures and recycling infrastructure in both developed and developing countries. But while it’s widely known that plastics can be an issue for the environment, what isn’t often known is that the persistence of plastics in the environment is actually closely linked to how they are made.
The overwhelming majority of plastics are made using oil-based materials, meaning that, by their chemical nature, many plastics have no oxygen content. This makes them very hydrophobic (water hating) and, as such, it is very difficult for common bacteria or enzymes to break them down if they enter the environment.

Over the past few decades, there has been increased awareness of our dependence on a limited oil supply and this has driven research into alternative, sustainable sources of chemicals. In particular, the concept of using bio-based materials as a resource rather than oil-based materials has really gained momentum. Sustainable bio-based material can be waste crops, waste wood, waste food – in fact, any waste biological matter.
Most importantly, these natural, bio-based materials can easily be broken down into smaller chemical building blocks – called “platform molecules” – which in turn, can be used to make other useful chemicals, including plastics.
Nature’s building blocks
Using these platform molecules, the Green Chemistry Centre of Excellence at the University of York, has been working with the plastics industry to create a new generation of bio-based polyesters. These are often used to make fibres for clothing, as well as films and containers for liquids and foods. The resulting materials are entirely plant based, recyclable and – importantly – fully biodegradable.
Aside from sustainability, the huge benefit of using biomass as a resource is the high quantity of oxygen that is incorporated into nature’s chemical structures (celluose, glucose etc). By using bio-based materials to make bio-based plastics, the oxygen content is kept in the material. The hope is that by having a high oxygen content, the bio-based plastics will have high, but controlled biodegradability. This means that the bio-based plastic can totally and safely break down into benign starting materials.
But although this new generation of sustainable plastics is a huge step forward, and a compostable plastic is of huge benefit, this is by no means the end goal for all bio-based plastics.
Circular economy
The circular economy is all about keeping resources in a constant loop, reusing and recycling them as many times as possible. This helps to minimise waste and reduce the need for brand new resources.
Treating plastic waste as a resource rather than a problem is an important change than needs to happen over the coming decades. This will help to preserve our remaining chemical materials, as well as protect our environment.

Enough plastic is thrown away each year to circle the earth four times.
Plastics are a fundamental part of modern society and they are here to stay. Ultimately, society has to move away from oil-based products towards sustainable bio-based alternatives. But regardless of whether a plastic is oil-based or plant-based, the biggest impact you can have on the life cycle of a plastic product is to reuse and recycle it.
As a consumer, this means you have a choice and the power to make a positive impact. Find out where your nearest plastic waste recycling point is and look to promote home collection and the proper recycling of all types of plastic waste.
So next time you use the last of the ketchup, help to preserve our resources by making sure your plastic waste stays in the recycling loop.