Why bio-bags are not the answer to the plastic litter crisis
September 20th, 2017
The real truth behind the ‘Bio-Bag’
The plastic bag was a fantastic invention – lightweight, strong, flexible and waterproof– it transformed the way we packaged goods and carried them home from the shops.
However, in the last decade or so we have come to recognise the downside of plastic – it is remarkably durable, and it is this aspect of plastic that has led to the world’s oceans approaching crisis point, as 80% of the plastic litter on land will find its way into the sea – which is a very scary prospect.
Even worse, ordinary plastic becomes embrittled and creates micro-plastics, so it is no longer acceptable to use ordinary plastic for everyday items.
Many countries are either banning or taxing plastic bags in an effort to reduce litter or switching to bio-based or ‘compostable’ bags made from crops such as corn-starch or sugar cane. Because they believed the hype – bio-bag sounds environmentally friendly – but they failed to read the small print.
Bio-bags (sometimes called compostable or hydro-biodegradable) are made in accordance with ASTM D6400 and EN13432, to biodegrade in the special conditions found in an industrial composting unit. These units are few and far between.
EN13432 and similar standards require 90% conversion to CO2 gas within 180 days, so it does not make compost, or anything useful for the soil and CO2 is a powerful greenhouse gas.
Bio-bags cannot be recycled as they will contaminate the recycling stream.
They are not suitable for shopping bags as they are not nearly as strong and are a lot more expensive to produce and transport.
Perhaps the most important point – we should not be using land and water resources to grow crops to make plastic especially when there are so many people in the world without enough to eat. The European Parliament have resolved not to encourage the use of land and water resources to produce bio-fuels – and the same reasoning applies to bio-plastics.
In addition to all of the above – these plastics do not address environmental concerns about litter, because they do not biodegrade in the open environment – which means that if they escape collection or responsible disposable they are no better than conventional plastics.
A consortium of Friends of the Earth, Surfrider foundation, Zero Waste Europe, Ecos and the European Environmental Bureau published a paper in 2017 in which they say “The bioplastics industry use their green sounding credentials to position themselves as helping to speed the reduction of fossil fuel use and solving the ever-growing plastic pollution and marine litter issues. There is clear evidence that bioplastics do not solve many of these problems and in fact may create new ones.”
So what can we do? The only viable solution to the plastic litter problem at the present time is Oxo-biodegradable plastic (OBP), which converts into biodegradable materials if it gets into the open environment at the end of its useful life. OBP products are tested according to ASTM D6954 to prove that they are biodegradable and non-toxic.
OBP is made from polymers such as PP and PE, and includes a metal salt, which does not break up the plastic but instead breaks up the molecular chains within the polymer so that it is no longer a plastic, and has become a food-source for microorganisms in the open environment.
OBP products can be made in existing plastic factories with existing workforce and machinery at little or no extra cost, which means the switch to OBP can be speedily implemented. They can also be recycled if collected during their useful life. But – if they escape collection and end up in the open environment, they will degrade and biodegrade, on land and sea, until there is nothing left, no fragments of plastic and no toxic residues, in the same way as a leaf – only quicker.
If governments are truly interested in protecting the environment from micro-plastics – Bio-based packaging and bags are definitely not the answer.
Governments in Africa, Asia and the Middle East are leading the way and have legislated to make OBP mandatory – because they studied the science and they know if works. They found that OBP offered an insurance policy. It promises that if the plastic packaging or bag escapes into the open environment, it will not be there for decades. It also allows shopkeepers and consumers to keep the best product for the job, without the environmental baggage associated with it.