A ‘self-destructing’ plastic has helped define a new British Standard for biodegradability.


OUT IN THE North Pacific Ocean is a vast mass of floating debris, christened The Great Pacific Garbage Patch. Comprising two expanses of human-produced rubbish – one near Japan, the other between California and Hawaii – its total area has been estimated at 620,000 square miles (three times the size of France). There are similar, if not quite so large garbage patches in all the planet’s other oceans, amounting to over five trillion pieces of plastic in all, according to environmental charity The Ocean Cleanup.

In 2017, in an effort to highlight the problem, a group of environmentalists petitioned the United Nations to recognise The Great Pacific Garbage Patch as an official nation, calling it The Trash Isles. They designed passports, currency and a flag; they invited members of the public to become citizens (Al Gore was the first) and even established a monarchy, appointing the actress Dame Judi Dench as queen. Their ultimate goal? To officially oblige other nations to clean up The Trash Isles.

But cleanup is only one part of the problem: adding to it is the other. And with a material of such persistence as plastic, it’s a big one.

One solution would be a type of plastic that would biodegrade – and truly biodegrade, rather than just turning one piece of plastic into many smaller fragments – before it washed down our rivers and into our oceans.

This is the ambition driving a British company called Polymateria. It has developed a process to manufacture plastic it says decomposes harmlessly in the natural environment. It involves mixing an additive in with normal plastics during manufacture to create food and drink packaging, shrink wrap, bubble wrap, fruit nets, plastic bags and the like.

Although it can be recycled in the normal way, what’s more is that – should it get discarded as litter – instead of languishing on roadsides, at fly-tipping sites and eventually ending up in the rivers and the oceans like so much normal plastic, it will decompose into harmless waxes in a matter of months. Bacteria and fungi will digest these waxes, breaking them down into carbon dioxide, water and more microbes. Crucially, there are no microplastics left behind.

Polymateria are calling it “biotransformation”. Once the technology comes to market – it’s currently being tested in a handful of countries, including the UK – it could totally transform the packaging industry, and the volume of persistent waste it produces.

Niall Dunne is Polymateria’s CEO. When it comes to plastic litter, he explains, there is one type that plagues us more than any other. They are called polyolefins, and they include polyethylene (plastic bags, packaging etc) and polypropylene (plastic cups and cutlery, bottle caps and containers).

A comprehensive 2016 review of plastic production found that of 8.3 billion metric tons of plastic ever produced, 6.3 billion has become plastic waste – and of that, just nine percent has been recycled.

More specifically, in 2016 Polymateria’s scientists estimated that at least 42 million tonnes of polyolefin packaging end up in the natural environment every year (and growing). “They are the most littered plastic on Earth,” Dunne tells National Geographic UK.

Consumers, he says, will initially be encouraged to recycle his product, which is comprised of modified polyolefins. The plan is to stamp a “recycle by” date on each piece of plastic. But should the packaging end up as litter, once it’s exposed to the elements, it will biodegrade anyway. “In lab tests that mimic ambient real-world conditions, our polyethylene waxes will go back to nature in 226 days, and our polypropylene waxes in 336 days,” Dunne explains.

This plastic will auto-destruct in…
So how can he be so precise? Polymateria have a laboratory in the White City campus of Imperial College, in west London. It’s here, in collaboration with the British Standards Institution (BSI), that they have developed rigorous testing standards for their biotransformation process. They use machines called weatherometers to measure the controlled weathering of their plastic under the influence of light, moisture and temperature. The key step as far as real-world use is concerned: increasing or decreasing the amount of a special additive they mix with the plastic, depending on how long they want it to last before it starts to biodegrade. The plan is that it first remains stable – in a dormant state – on warehouse and supermarket shelves, but later, once it’s exposed to the elements, it triggers its own degradation via multiple chemical reactions within the material.

So far, so remarkable. But how exactly does biotransformation work? This is where things get tricky. Understandably, given the enormous value to Polymateria of this new technology, they are keen to keep the precise details close their chests. “Secret squirrel stuff,” is how Dunne describes it.

This is what they will reveal, however: that all-important additive (containing “around a dozen different components, including oils, rubbers and desiccants”) is mixed in with the normal polymers at the manufacturing stage of the plastic packaging. It comes in the form of oval pellets, around half a centimetre long and half a centimetre wide – known in the industry by the generic term ‘masterbatch’. The formulation and strength of the additive varies, depending on which function each batch of plastic is designed for. Plastic cups obviously need to be stronger than cling film, while the plastic wrapping around a new pair of underpants needs to last longer than the plastic net containing lemons.

Once exposed to the elements, the additive triggers a catalytic process, cutting the links in the polymer chains to produce smaller chemical compounds. Light, air and moisture are then all able to work on the plastic until it becomes a wax which is then digested by bacteria and fungi.

The indoor and outdoor weathering cycles were developed by independent labs in Florida and Scotland, with the chemical transformation of the material into biomass, water and carbon dioxide validated by a technical group facilitated by BSI. Ecotoxicity tests have ruled the resulting wax non-harmful for contact with soil, plants and the aquatic environment.

This notwithstanding, the company are keen to stress this decomposition process is for ‘fugitive’ plastics only – i.e those that have escaped the normal process of recycling. Polymateria insist their additive has “no adverse impact on recycling streams”.

Right now the pellets are being manufactured in a factory in the French city of Clermont-Ferrand – with a capacity of 5,000 tonnes a year – but Polymateria are in talks with the Indian government about a far larger facility in that country. In fact Asia, which has many countries struggling with plastic litter, is the region they have their sights set most firmly on.

The brains behind biotransformation is Polymateria’s senior vice-president of innovations, Dr Christopher Wallis. This materials scientist joined the founders of the company – Jonathan Sieff and Lee Davy-Martin – in 2016. “I knew these guys had the acorn of an idea but it needed to be developed,” he tells National Geographic UK. “There wasn’t a eureka moment. It was an iterative process.”

A new standard
Wallis believes his company is the only one on the planet with the proven technology to biodegrade these types of polyolefin plastics. “I know of other technologies out there, but I don’t think anybody has gone to the nth degree of validation beyond standardised testing,” he says.

The company’s marketing materials make an even stronger assertion. “We are the only plastic material that truly biodegrades,” it claims.

“The need for an overhaul of standards assessing biodegradation of plastics has been recently recognised in the UK”, says Dr Dannielle Green of Anglia Ruskin University, who was involved in the validation of the new British Standard. “The standards landscape needs to be ever evolving, with standards themselves like living entities, being updated every few years to reflect the growing science and to increase their relevance to the real environment,” Green told National Geographic UK in an email – citing a 2019 call for evidence consultation by the British government to gather scientific opinion on the matter.

“The standard is a step in the right direction, and the interdisciplinary collaborative approach used by BSI is exemplary,” she adds, “but I think there is still a lot to do globally to make standards assessing biodegradation of plastics in all habitats  – soil, freshwater and marine – more environmentally relevant

Into the real world
In several countries around the world, Polymateria has already mixed its additive with plastics used on certain commercial food packaging. The company won’t reveal which brands and which products, but they did say they were on supermarket shelves in the UK, Spain, Portugal, Taiwan and Kenya. “We are testing in India, and due to launch soon,” Dunne added. “And we are talking to manufacturers in China and the USA.”

Of his material, Dunne is confident. “It will have a [BSI] Kitemark and a catchy name, [and] a clear and simple call to action.” This, he says, will help counter the proliferation of ‘greenwashing’ found on other packaging designed to look environmentally responsible, but that doesn’t always live up to the claim.

“I’m an optimist and believe that most people will do the right thing, but have been incredibly confused by the eco-labelling jungle we have created around packaging,” Dunne adds. “We provide a clear time frame within which responsible disposal needs to happen. If the system fails and biodegradation is needed, claims can be substantiated against a bedrock of scientific proof through the new BSI PAS [Publically Available Specification] Standard, which hasn’t been the case previously.”

He envisages a future where the technology is used in all sorts of disposable plastics: biscuit and snack packaging, for example, and tea bags, hygienic wipes, food pouches, meat and fish packaging, coffee pouches, ice cream tubs and PET drinks bottles.

If this sounds too ambitious, it’s worth noting that on the company board there are two individuals with extensive track records in the world of retail. The chairman is Marc Bolland, former CEO of both Marks & Spencer and Morrisons, while another member is Simon Susman, former CEO of Woolworths Holdings and former chairman of Virgin Active Holdings. All are people who could really help make a sea-change in the plastic packaging industry.

But what do the environmentalists think? Lillygol Sedaghat is a National Geographic explorer and storyteller, whose research has focussed on plastics, waste management and sustainability in the Asia-Pacific region. She sees Polymateria’s breakthrough as a “scientific and innovative feat”.

“Its potential for impact is significant, particularly if it can fit nicely into the systems and machines already being used to produce common single-use plastic materials by large, wide-reaching companies,” she tells National Geographic UK. “This may be the first of many steps in the transition to a more sustainable future.”

International take-up (and breakdown)
However, Sedaghat warns of potentially unknown implications when the biodegradable plastic is used in different regions or climates, or by people of different cultures and consumer habits. “What happens when the product enters a subtropical monsoon climate of Bangladesh versus the subarctic zone of Canada?” she asks. “When it is used as a single-use sachet in northern India versus a boba milk tea cup in Taiwan? Different cultural and ecological scenarios often call for localised solutions, so how can this product be

adapted to meet all the different contexts in and of the world?”

Nevertheless, she remains optimistic. “Based on what I’ve read, this innovation has the potential to solve the current problems of poor waste management, disposal, and toxic leakage into the environment and serve as a transitional piece to a new, more balanced future.”

Provided the testing goes well, Polymateria’s success will probably hinge on the canniness and scale of their marketing. There will be a slight additional cost to the packaging – Dunne estimates between 10 and 15 per cent – but it is hoped most consumers will agree to absorb this.

Anything to stop those Trash Isles from growing any bigger.

Source: https://www.nationalgeographic.co.uk/environment-and-conservation/2020/11/new-self-destructing-plastic-has-helped-define-a-new-british

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