The war on plastic: are alternatives always more sustainable?

Headlines would suggest that plastic should be on the run. From Greta Thunberg at the UN to Extinction Rebellion in the streets of major cities across the world, it has been made clear that consumers, particularly of younger generations, expect far more to be done to combat the climate crisis. Doing so obviously extends far beyond simply dealing with plastic and the sustainability of packaging but the mood has vociferously turned against ecologically damaging materials.

In response, manufacturers have certainly been moving to increase the recyclability and reusability of their materials (no doubt encouraged by the proposition of legislation that will force the issue). However, this does not necessarily account for the whole picture; while there is certainly a growing voice of support for sustainability, it would be brazen to assume that voice had wiped the slate clean when it comes to plastic. Although companies are shifting their approach, plastic is still one of the dominant manufacturing materials out there and unlikely to disappear in the short term.

Richard McKinlay, head of consulting at circular economy specialist Axion, says: “Consumption of plastic is increasing globally. With growing populations in Asia, the virgin plastics industry is booming. In contrast, the recycled plastics market has been stagnant for many years, with the focus historically being placed on the ‘low hanging fruit’ of post-industrial plastics and cleaner packaging such as HDPE and PET.

"However, in the last few years there has been a huge shift in mentality from the brands and retailers, and the demand for good quality recyclate is higher than ever. This is leading to more investment in recycling infrastructure.”

The key question to ask when looking to replace any material, sustainable or otherwise, is: can the alternative do the job to the same standard or better? Plastic is not only a widely used material but its properties are also proven to be ideal for products such as food, drink and pharmaceuticals.

While producers and retailers are trialling a number of alternatives, it is yet to be proven whether an alternative material can fully replace plastic.

Rosalia Ikonomov, marketing manager for fresh produce at responsible packaging producer Amcor, says: “Bio-based plastics made from renewable resources such as sugar cane, corn, or trees, can have similar performance characteristics to fossil-fuel based plastics, but have also faced their own challenges in attracting consumers to buy them.

"Some come with a cost impact, others are debated because the renewable resource might compete with food production and others are not compatible with the recycling stream and might even lead to additional contamination of recyclable materials.

“Biomaterials, therefore, have to look and feel good, have to have superior shelf-life, not cost a fortune to implement, and not come with other sustainability drawbacks. Some products, such as bio-based polyethylene for coffee packaging applications, already fit this bill, and we predict that increasing numbers of brands will start switching to these options.”

Perhaps the most convincing pushback to the wholesale demonisation of plastic, bearing in mind that product safety may be solvable with a diverse range of solutions and materials yet in development, is that sustainable alternatives may not be as sustainable as assumed. It is easy to look at the mass of plastic waste polluting the ocean and consider the material written off but the cost of other materials - in terms of energy requirements for production, for example - may be less visible and equally worthy of concern. This is not to say that plastic’s flaws should be dismissed, rather that they are not so unique and easily replaced.

Christina Valimaki, vice-president for segment research at Elsevier R&D Solutions, says: “There is no perfect option to solve the plastics crisis because every alternative has trade-offs that need to be considered. For example, we could stop using plastic bags for our shopping since we have a much more biodegradable option – paper.

"But the manufacture of paper bags uses 2.2 times more energy than the manufacture of plastic bags and 4.7 times more water, as well as emitting 3.1 times more greenhouse gases and 2.7 times more acid gases. Additionally, we’d need to cut down a lot more trees to meet demand. Other alternatives like aluminium and glass might be easier to recycle and reuse but they’re also more expensive, less durable and less malleable than plastic, which means our purchases get more expensive while also not being as well protected during transit.

“In some cases, careful planning might allow us to get rid of plastic, but we must exercise caution – eliminating plastic in a number of scenarios could also remove some environmental upsides. For instance, the plastic wrapping we use to protect our food helps ensure it doesn’t go off, if we get rid of it then we will almost certainly see a dramatic rise in food waste.

"This isn’t to say that we don’t need to drastically reduce our reliance on plastic, or that it isn’t causing huge environmental damage. But any path to weaning ourselves off plastic must involve a broad, transparent conversation about what environmental burdens we are willing to endure and which we aren’t.”