When plastic stops being plasticView(s):
Can a plastic substance help solve the ever-present plastic problem? Yes, says Thanula Wijewardena, promoter of oxo-biodegradable plastic. Smriti Daniel reports
Particularly in recent years Thanula Wijewardena, a wildlife enthusiast, has begun to chafe at the sight of plastic bags, bottles and other discarded materials all over the island. On a recent trip to Mannar he came away saddened by beaches covered in litter and plastic debris. “We have a problem with litter, with plastic that’s thrown away and doesn’t get caught in the recycling process or the collection process,” he says. He adds that even if it’s swept off our lands and into the ocean, it only joins an estimated 70 million tonnes of plastic just floating around.
As a solution to this kind of widespread littering, oxo-biodegradable plastics are being embraced by countries like Pakistan and the UAE. “It is basically the ideal solution that everyone is looking for,” says Thanula, “A lot of people are talking about corporate social responsibility, this is how they can do it.”
A plastic bag, like a diamond, can be forever. The moment you discard it after carrying your groceries home is merely the beginning of its long journey. Whether in a landfill, littering a sports ground, clogging the drains of a city or finding their way down some unsuspecting animal’s throat, bits of plastic can survive for centuries. It’s something Thanula is all too keenly aware of and it’s why he’s chosen to promote oxo-biodegradable plastic as an alternative. It’s the plastic you’re used to in every way except one – its manufacturers can decide when they want it to stop being plastic and become something else, something that will become part of the earth in much the same way a leaf or a twig would.
The oxo-biodegradable plastic is created by using d2W, a polymer-based additive. Thanula is the Managing Director of Megadynamix Pvt Ltd., the distributor for d2W in Sri Lanka and a passionate advocate for oxo-biodegrable plastics. In their brochures, d2W’s makers, Symphony Environmental Ltd. refer to it as ‘controlled-life plastic technology’ – a moniker inspired by how this plastic can be engineered to begin self-destructing at an appointed time. Depending on the formulation used that could mean as little as 60 days or as long as 5-6 years. “Using this doesn’t affect the physical properties of the plastic in terms of elasticity, strength or transparency,” says Thanula, “it looks and behaves like normal plastic.” d2W can be used in plastics of different strengths – from the kind you wrap your lunch packet in to the kind that would hold your baby powder.
It works by breaking down the molecular structure of the polymer, eventually turning it into a water soluble compound. Microorganisms present in the environment now begin to take an interest, and will ‘bio-assimilate’ it in the way they would any other organic material. They convert the product that was once plastic into water, carbon dioxide and biomass. The process will happen on land or water, just as long as oxygen is present. The speed of degradation itself is affected by levels of heat, light and stress.
A key ingredient in the recipe for d2W is drawn from a by-product of the petroleum refinement industry. Naphtha is usually just burnt off or otherwise disposed and the makers of d2W argue that they’re putting it to a better use. The additive is mixed into the basic polymer at the factory. Oxo-bioldegrogical plastic bags can be made with the same machines that generate normal plastic bags and are relatively affordable – Thanula estimates it’s 15% – 20% more expensive. The plastic can be recycled if collected before the deadline set by the manufacturers.
Oxo-biodegradables are now a part of a heated debate on how to cope with our planet’s overwhelming plastic addiction. To understand the issues, you first have to know that not all biodegradable plastics are made equal. Unlike oxo-biodegradables, some bio based plastics will only break down in the absence of oxygen. Labelled somewhat misleadingly as ‘compostable’, you can’t expect them to disappear in your home compost bin. Instead they need carefully regulated, industrial landfills which provide, among other things, an oxygen free environment.
Some bio based plastics are made with organic raw materials like corn, raising troubling questions about misusing what should be a food source and the critical forest lands that are razed to grow more crops. Also worth noting is that as these degrade, they generate methane, which will always lose a popularity contest to carbon dioxide – the less explosive greenhouse gas.
Oxo-biodegradables themselves are not without their issues. Environmental conditions like humidity and temperature play a key role in how quickly they degrade, and if the material is packed into a landfill where it is starved of oxygen, it won’t degrade. The other issue is what’s left behind. Symphony Environmental Ltd. say their products have passed the eco-toxicity tests in OECD 207/208; BS 8472 and ASTM D6954 to confirm they do not release toxic residues or heavy metals that could harm the environment. (In addition, Symphony says d2W conforms to EU and US requirements for direct contact with food if intended for that purpose.) However, a U.S study flagged some other brands when the leftovers were found to contain very high levels of heavy metals.
The fact is though that banning plastics isn’t feasible currently. Paper bags for starters come with a high environmental price tag and none of the features that endear plastics to us. “The general conception is that paper is more environmentally friendly than plastic,” says Thanula, explaining that this is not the case when you consider the former’s large carbon footprint – from the cutting of trees to production to transport. While recycling and reusing old bags would be great, we don’t do enough of it.
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