13th January 2017
Bioengineers at The University of Nottingham are trialling how to use shrimp shells to make biodegradable shopping bags
It is true that conventional plastic is made from oil, but it does not deplete the planet’s oil resources. This is because oil is extracted to make fuels and because plastic is made from a by-product of oil refining that used to be wasted. While we have this resource it makes sense to use it, and oil depletion is not therefore a reason to be against conventional plastics or to look for alternatives. The reason why politicians and environmentalists are against conventional plastic is because it will lie or float around for decades if it gets into the open environment as litter.
However, there is now a type of plastic called oxo-biodegradable (Controlled-life) plastic (see www.d2w.net). It can be made in existing plastic factories using existing workforce and machinery at little or no extra cost, so it can be implemented right now. It can recycled with other plastic items, but if it does escape collection and ends up in the open environment, it will degrade and biodegrade on land and sea in the same way as a leaf only quicker, and leaving nothing behind. No toxic residues or fragments of plastic, and it will not be around for decades, as conventional plastic is now.
Oxo-biodegradable plastic offers a practical solution to a difficult problem – a fact that has been recognised by countries in Asia, Africa and the Middle East who have legislated to make this type of plastic mandatory.
Plastic made from shrimp shells may take 10-15 years to develop and become commercial, but there is no real need for it, and it may use even more fossil-fuel to collect the shells and transport them to a factory, and then to run the polymerisation process. Nor do we know whether it will biodegrade in the open environment (as distinct from an industrial composting environment). Let’s keep shrimps on the inside of the packaging and oxo-biodegradable (controlled-life) plastic on the outside.