The Ellen MacArthur Foundation’s New Plastics Economy initiative recently published a statement calling for a ban oxo-degradable plastic packaging. Oxo-degradable plastics, most commonly used for carrier bags and food packaging, are actually contributing to pollution and pose an environmental risk as they break down and enter our coastal and marine areas. These microplastics are becoming an inescapable part of our marine ecosystem, even entering our food chain. Therefore, a host of signatories are adding their voice to the call for a complete ban.
Starting from this point, I think it’s useful to discuss the overall concept of alternative plastics. As the environmental problems related to plastics are becoming a central element of the global agenda (see the recent decision of UNEA for zero tolerance to plastics) the efforts to develop alternative materials are rapidly increasing. Today there is a bioplastic alternative for every plastic available.
The core of the efforts is rather simple: we need new materials, preferably branded as more “natural”, with, more or less, the same structural and functional properties but with different end of life behaviour, when they become parts of a waste stream. Shrimp shells and algae are just two of the natural materials scientists are working with to develop more “sustainable” types of plastic. Although currently the so-called bioplastics represent almost 1% of the plastic production, and the whole sector is expected to have a US $ 7.5 billion value in 2022, the relevant research and innovation is very dynamic.
But what is the meaning of the more “sustainable plastics”? The case of oxo-degradable plastics is very characteristic. Oxo-degradable plastics are plastics containing a series of chemical additives intended to accelerate the oxidation and fragmentation process, leading, theoretically, to a more speedier degradation. However, the degradation process is depended on too many variables and in many cases, it’s finally behaving like the usual plastics. Research by the New Plastics Economy Initiative has concluded that oxo-degradable plastics are simply not suited for effective long-term reuse & recycling. The statement from the foundation was left in no doubt that this type of plastic is detrimental to our environment “the evidence to date suggests that oxo-degradable plastic packaging goes against two core principles of the circular economy: designing out waste and pollution; and keeping products and materials in high-value use.”
Oxo-degradable plastics are simply not suited for effective long-term reuse & recycling
In general terms, complete biodegradation of plastic occurs when none of the original polymer remains, a process involving microbial action; i.e. it has been broken down to carbon dioxide, methane and water. The process is temperature dependent and some plastics labelled as ‘biodegradable’ require the conditions that typically occur in industrial composting units, with prolonged temperatures of above 50°C, to be completely broken down. Such conditions are rarely if ever met e.g. in the marine environment.
ISWA’s 2014 paper on plastics pointed out that the excessive and uncontrolled use of additives in manufacturing such plastics is leading to substantial human exposure and environmental dispersion. Most compostable plastics, for example, can’t simply be chucked in your garden, he explains – they need to be sent to an industrial composting facility. And while people may assume that bio-based products are all biodegradable, many are not. Coca Cola’s Plant Bottle, for example, though partly derived from sugarcane, is chemically identical to hard-to-breakdown polyethylene terephthalate (PET) bottles. On the plus side, it can be recycled many times; on the downside, it won’t breakdown for centuries.
Alternative plastics are just a small fraction of the huge efforts made around the world to develop new materials that will substitute oil based products – but as we have learnt from the previous industrial revolutions, each new material represents a potential new headache for waste management systems. Unfortunately, while the new materials are applied in different sectors to improve certain functional requirements, when they become a new massive waste stream they usually face completely unprepared waste management and recycling systems. But this is just one part of the problem. There are three more aspects that should be discussed (I assume that green-washing could be another one, but it’s not part of this article).
Biodegradable does not mean sustainable
Let’s suppose that we have a fully biodegradable plastic, that is capable to perform its degradation fast enough, as it is theoretically designed. Still, if it will be found inside the sea, it will be considered as food by fishes. Still, it will be degraded in microplastics that will be like plankton. The only difference will be that it will degrade faster, but still in the order of several years. According UNEP, the adoption of plastic products labelled as ‘biodegradable’ will not bring about a significant decrease either in the quantity of plastic entering the ocean or the risk of physical and chemical impacts on the marine environment, on the balance of current scientific evidence.
Of course, there other cases, like the soluble pods that allow washing products to be delivered in concentrate form that really can save energy and materials. So, there is a need to check specifically the use of each product and what are the alternative materials it substitutes, before we conclude which material is better for the specific use.
Alternative does not mean better
A recent trend is the development of plastic-like materials, some of them compostable under certain conditions, from food scrap. As Tom Szaky, the CEO of Terra Cycle, commented although they’ll degrade, they won’t degrade back into anything like the nutrient- rich earth at the start of the process. “It doesn’t make environmental sense to take a plant, turn that plant into a highly-refined petrochemical, only to then use it once and have it turn into something effectively worse than soil,” he says.
Alternative plastics or alternative business-as-usual?
Unfortunately, in many cases, alternative plastics are only promoted to continue the tremendous use of plastics as we already have been done for decades without any change to our disposable culture and with the minimum disruption of the plastic industry. Sorry, this is completely unacceptable.
More than 9 billion tons of plastic have been made since the 1950s, and the vast majority of it has been thrown in the trash, says a new study made by a team of researchers from the University of California, Santa Barbara, the University of Georgia, and the Sea Education Association. They also estimated that the amount of plastic in use now is 30 percent of all the plastic ever produced and roughly 7 billions tons of plastic are trashed. With the recent findings about plastic pollution and marine litter, we know well the vast environmental and health impacts.
We can’t continue like this. Although alternative plastics can be useful, they can’t be an excuse to continue the production of more and more plastics. The real alternative is to gradually eliminate single use plastics, to change our disposable culture, to consider longer life cycles of the plastic products, eco-design and stimulate reuse. Without such a shift, alternative plastics will be more a business-as-usual than an environmental friendly alternative.