The scourge of plastic and its headlines are an unavoidable part of modern life. No corner of the planet or media platform is free from the pervasive and relentless ability of plastic to stick around unwanted. Remains of supermarket bags, lumps of polystyrene, the straw epidemic, drinks containers and miscellaneous masses found in the ocean, marine animals stomachs and strewn across beaches serve as constant reminders on news feeds and TV broadcasts that our most ubiquitous material will doggedly pervade the Earth for centuries to come. And it is still increasingly difficult to buy products not incarcerated in the stuff.
Plastic as an adjective classifies a type of material that can be moulded into a solid form. Inspired by the long flexible chains of molecules that form a polymer, the modern poly-material was named after this defining property. In most material compositions, organisms can consume the molecules in the structure and convert them into natural matter. The decomposing of organic solids is biodegradation, similar to the process that happens in our stomachs and compost heaps. But petroleum-based polymer chains consist of huge molecules that no organism has evolved to polish off, so solid petro-plastic waste remains molecularly unchanged. Organisms contempt for poly-plastic is what gives it the presumed infinite lifespan, where the structural integrity may break down, but the particles will get smaller and smaller yet will never entirely be removed from the environment. The refusal to decompose makes petroleum-derived plastic ideal for applications of things that are designed to last for hundreds of years like bridges, nuclear waste casings and space shuttles. But for packaging designed to last the short-lived longevity of food, non-biodegradable plastic is decidedly less necessary. Industry has long been batting off environmental concerns with notions of plastics ability to reduce wastage by protecting goods and preventing food waste. But the global impact of human detritus is garnering demand from consumers, governments, and the media for commerce to seek alternative packaging materials.
Advocates for a switch from plastic have often looked to existing materials like glass, metal and cardboard as replacements. But a study by independent environmental researcher Trucost found that though the environmental impact of the alternatives is lower than plastics per kilogram, the amount required to perform the same job as plastic is often more environmentally costly. In food packaging, almost five times the amount of glass, metal and cardboard is required to do the same job as plastics. The study estimates that material substitution with existing alternatives would increase the environmental cost of packaging from $139 billion to a total of $533 billion.
Plastics derived from naturally occurring sources that will biodegrade in the natural environment rather than its petrochemical predecessor have long been theorised as the viable alternative to achieve the same material benefits in equal quantities without clogging up every orifice of the planet. Popping ‘bio’ on the end of a material known for ecologically harmful effects sounded like the ideal solution, but early bioplastics were more sustainable as an ideological concept than practical application. Largely a laboratory experiment for the last few decades, the first generation of bioplastics failed to meet the lesser environmental costs necessary to make it a strong contender. In the 1990s, naturally derived plastics used the sugars from corn, sugar cane and other food crops as raw materials. But the irony is that hotter temperatures, one of the drivers of bioplastics, reduces the fertility of agricultural land. Diverting food crops for material rather than actual food, with a growing population and reduced arable land made original bioplastics a significantly unsustainable innovation. Companies that eagerly made the initial switch like Innocent and Anson, one of Britain’s largest suppliers of plastic food packaging, soon returned to conventional plastic.
Recent reiterations of bioplastics have restored some environmental credentials. The key breakthrough was the development of technology capable of cheaply extracting sugars from agricultural residue, tree waste, grasses, algae and even methane instead of food crops. The new development exploded the market for bioplastics, which is estimated to grow by almost 20% between now and 2022. Companies have flooded in for a piece of the market, bringing with them a deluge of greenwash, tacking ‘sustainable’ ‘biodegradable’ and ‘compostable’ on to every available surface and campaign. In 2016, the furniture giant Ikea announced a decade’s long campaign towards renewable, bio-based materials. Packaging company TetraPak, famed for its notoriously difficult to recycle cartons, have rolled out TetraRex, it’s first fully biologically-derived cartons with the aim of eventually making all its products from renewable sources. Even the petroleum giant Lego has made huge steps towards naturally derived plastic for their little bricks. Most notably, Coca-Cola made the courageous and heavily marketed step to introduce a 100% bioplastic version of its “PlantBottle” after manufacturing 35 billion bottles using a 30% bio-based plastic since 2009.
The greenwash of many companies has served confusion alongside leaves and arrows to denote safety for the environment. Even the prefix of ‘bio’ with ‘plastic’ is a dangerous generalisation. Traditional bioplastics are made from naturally derived materials but are not required by material standards agencies to be biodegradable. Such materials have questionable environmental credentials as though they reduce oil usage; the plastics will continue to pollute the environment since like petrochemicals they cannot be broken down. Whereas materials classified as ‘biodegradable plastics’ do not have to be derived from natural sources. These synthetic polymers can be engineered from petroleum with additives to make it break down, but the unnatural composition leaves toxic residues behind. This bio-confusion has made for easy green points for corporate social responsibility teams. Brands are proudly proclaiming ‘recyclable!’ and appending ’bio’ to words, fail to acknowledge that the market pull is coming from repulsion of the ocean being used as litter tray for post-consumer product.
Simply and idealistically, plastic made from plants will break down into plant matter, but even with bio-based plastics that are capable of biodegradation, the confusion continues. The range of natural materials they can be derived from means that there are countless versions of such bioplastics, each with specific optimal conditions for total material breakdown. Some bio-based plastics made from agricultural waste are created in such a way that they will fully break down in a matter of weeks in home composting and marine environments into natural sediment. But other bioplastics like PLA; polylactic acid derived from sustainably questionable corn plants, do not afford the same ease of disposal. PLA is made to replace PET for drinks bottles, and to ensure the durability required for liquid packaging they undergo intensive manufacturing processes. These more sturdy bioplastics require industrial composters with very high temperatures and humidity to break down into organic particulate. In the absence of the correct conditions, for example in landfill, the ocean, or your compost heap, these naturally derived plastics much like conventional can take centuries to degrade. To make matters more confusing, plastic #7, the catch-all category for all ‘other’ plastics, including Polycarbonate which is known to contain the ill-famed hormone disruptor BPA, also includes bioplastics. So the little seven in a three arrowed triangle stamped on the bottom of a bottle could mean carcinogenic, or friend to the ocean.
The public should not be expected to be polymer experts to discern natural from synthetic, degradable or biodegradable. But with little available information, the responsibility is left to the consumer to dispose of identical correctly, yet potentially damaging packaging. And like all good tenants of the planet, if it looks like plastic and feels like plastic, chances are, it’s going in the plastic recycling bin. But in this plastic infested world that puts the business end of plastics in the hands of the consumer, it’s not that simple. Bioplastics are not readily recyclable as mixing plant-based material with oil-based contaminates the material outcome and makes it unsaleable. In the UK, recycling companies and local authorities actively refuse to handle them as that the cost of investment in expensive new processors is unfeasible to extract bioplastic from waste for recycling. Such reluctance comes into direct confusion with increasing efforts from the UK government and companies that are pushing for 100% recycling, while simultaneously developing bioplastics for the next most prominent material. Bioplastics rejected by recycling facilities end up in landfill sites which are specifically built to prevent biodegradation to prevent groundwater contamination. They are sealed top and bottom in an oxygen and microbe-free environment which effectively mummifies waste. In sealed landfills, without the correct heat and moisture conditions, bioplastics will not degrade. Actively managed landfills, designed to foster biodegradation, yield and capture methane from the waste, yet in the UK few sites capture the off-gas, and much of it is released into the atmosphere. The commercially ideal end of life facility for products made from plant starch plastics is a commercial composting facility, but the UK is severely underprepared for a commercially composting designation. Of over three thousand waste disposal facilities 473 are active anaerobic digesters, and of that 30 % take packaging. The total statistic amounts to just 4% of total waste disposal sites in the UK are prepared to accept bioplastic material.
It took over half a decade for reasonably effective recycling systems to manage the recovery of plastics, yet just 9% of the 350 million tonnes of plastic created around the world globally is being recycled. It is the unmanaged loss that occurs somewhere between the bin and the waste disposal site that results in 8 million tonnes of plastic ending up in the ocean. It is clear that globally waste disposal systems are still not equipped to handle the amount of waste human society produces. For bioplastics to require specific conditions and facilities to break down, the goal for fewer gyres of litter floating in the ocean is not achieved. Future bioplastics must be designed to entirely break down harmlessly in naturally occurring conditions.
Markets and governments around the world acknowledge that it’s time to start phasing out the conventional plastic. Globally, emboldened by the Paris climate talks, nations and companies are regularly committing to new ways to find alternatives to fossil fuel dependence. France recently banned non-biodegradable plastic cutlery, plates, and cups. The UK has followed suit with promises to halt plastic straws, stirrers and cotton buds, and bans on plastic bags and other waste are increasing across nations, and bioplastics are ranking high on the agenda. Europe is the largest market for bioplastic packaging, holding almost a third of the shares in global bioplastic packaging consumption. Though by 2022, Europe will account for less than 10% of bioplastic production, which will be dominated by Thailand, India and China. Oil-poor nations that are resource dependant on other countries for the asset, like Europe and South America, are set to grow in material independence as the bioplastic market grows.
Innovations in materials that replicate the properties of plastics are being created from mushroom cultures, algae and even capturing methane to produce a solid mass. Countless material pioneers and scientists are working tirelessly to create a world where societal requirements do not come at an environmental cost. But it has taken 30 years for bioplastics to reach this inconsistent stage. While traditional petro-plastics are continuing to be produced and discarded of in millions of tonnes into the ocean, and current naturally-derived plastics are suffering the same fate, does the planet have time to wait for the research and development of bioplastics 3.0?