Oxo-biodegradable plastics

BY: Michael Laurier
• Plastic bags are useful but become a sanitation and environmental problem after use.

Ghana will not be the first to impose a ban on lightweight plastic packaging, nor the first to find that their good intentions have unintended consequences.  The reality is that plastic bags are much too useful to be banned. There is nothing as cheap, strong and flexible to replace them when it comes to carrying food and other goods and protecting them from damage or contamination.

However, the very property that makes plastic indispensable, namely its durability, also means that it can lie or float around in the environment for decades, causing a visual intrusion, endangering wildlife and clogging watercourses, which contributes to flooding.

An article by Dr Frank Essien for ghanaweb.com ( February 5, 2014) stated that “85 per cent  of the solid waste dredged from choked gutters around the Market Circle in Takoradi was made of plastic from sachet water”, a scenario that is likely to be repeated in cities all over Ghana. 

 

Contrary to popular belief, paper bags are not a viable option. They disintegrate when wet, are not as strong or flexible and cost more to produce and transport.  Moreover, they are worse for the environment because are used a lot of energy and noxious chemicals to manufacture them.

Oxo-biodegradable plastic

The good news is that there is no need to ban lightweight plastic bags because the problem of plastic waste accumulating in the environment can be solved by switching to oxo-biodegradable plastic. Oxo-biodegradable plastic is conventional polyolefin plastic to which has been added a small amount of a metal salt. This causes the plastic, at the end of its useful life (in the presence of oxygen), to change into a biodegradable material which can be bio-assimilated by microorganisms in the environment in the same way as a leaf, only quicker, and leaving nothing behind; no toxic residues and no fragments of plastic.

If collected during its useful life, it can be recycled along with other plastic products, which means that the many people whose livelihoods depend on plastic recycling will not be affected, as plastic packaging and water sachets can both be made with oxo-biodegradable plastic. If it does not get collected for recycling and ends up in landfill, oxo-biodegradable plastic is inert, unlike bio-based plastic which generates methane, a powerful greenhouse gas.

Consumers will not notice the difference as it looks and feels like conventional plastic and manufacturers will be happy because it can be made by local plastic factories with their existing machinery and workforce, at little or no extra cost, thus protecting jobs in the plastics industry.

The important distinction is that the useful life of oxo-biodegradable plastic can be controlled at manufacture, after which it will degrade and biodegrade in months, rather than years, on land or sea.

Symphony Environmental Technologies Plc, a British Public Company, has already been supplying some manufacturers in Ghana who are now making oxo-biodegradable plastic.

At a conference in Lomé in June this year, chaired by the Environment Minister of Togo, the representatives of seven West African states agreed that oxo-biodegradable plastic was essential to protect the region from the accumulation of plastic waste in the environment.

Eleven countries in Africa, Asia and the Middle East have already legislated to make oxo-biodegradable plastic mandatory for a wide range of consumer products. This is not only environmentally beneficial but also an economically sound decision because it works - allowing consumers and shopkeepers to keep the plastic but dispose of the environmental baggage associated with it.