Waste packaging –a sea change for bioplastic?

The European Union and public opinion are set to change radically the plastics industry, by requiring waste plastic collection and recycling.  But will this be good or bad for the emerging bioplastics industry?

The public has become acutely aware of waste plastic in the world’s oceans with dire predictions like  by 2050 oceans are expected to contain more plastics than fish (by weight)’[1].  At first it was plastic micro beads but now concern has spread to all plastic packaging. A petition in the UK to ban non recyclable/non-compostable packaging[2] has gained over 84,000 signatures.

International brands are reacting too. Unilever recently committed to using 100% recyclable packaging by 2025. P&G has announced a limited edition of Head and Shoulders hair shampoo in a bottle made from beach plastic.

The European Commission published a “Strategy on Plastics in a circular economy”, [3]which seeks to decouple plastics production from virgin fossil feedstock, reduce life-cycle GHG impacts, increase the uptake of plastic recycling and reduce plastic leakage into the environment. The potential benefits of biodegradable plastics are recognised, but qualified with warnings that they might discourage recycling. In fact bioplastics fit well into a strategy for plastic packaging, which has to contain more options that just recycling.

The Ellen MacArthur Foundation has examined the problem of waste plastic in detail in a new report, The New Plastics Economy Catalysing action 2. The report shone a light on two important issues that are often overlooked in the discussions about plastics recycling. The first is that small items (40-70 mm) make up about 10% by weight of plastic packaging but pass by recycling sorting machines and go direct to landfill. These items (sweet wrappers, fastenings, lids, sachets, caps), are so light that some are blown out of tipping areas of landfills and into the environment. The report proposes that these small items should be redesigned to remove this problem. Furthermore it makes sense that if they can’t be redesigned, they should be made from biodegradable polymers, so when they end up in the environment, they biodegrade. Biodegradable polymers are usually made from biomass so this would provide a new market for bio-based plastics. This solution is already on the market for micro-beads[4].

Another important finding is that many waste food containers can’t be economically recycled because they are too contaminated with residual food. The report proposes that certain food containers should be compostable with food waste. Compostable polymers like PLA (polylactic acid) are made from biomass and are already commercially available[5]. They just need a regulatory pull to scale up further.

So there is a rationale that bio-based compostable and biodegradable plastics have a place in the framework for tackling waste plastic. Some governments are already introducing exemptions for these plastics in their new packaging regulation.

There is another type of bioplastic. They are designed to be ‘drop-in’ replacements for the most common types of durable fossil plastic. These durable plastics will always be needed for packaging applications where compostable or biodegradable plastics are not suitable.

Drop-in bioplastics such as green PE (polyethylene)[6] made from sugarcane can be recycled with their fossil counterparts, with the added benefit that they have a much lower carbon footprint. This becomes important when plastics eventually need to be disposed of, as they can only be recycled a finite number of times.  Disposal routes, other than landfill, involve some type of incineration or burning which result in the emissions of the greenhouse gas carbon dioxide. When bioplastics are burned, the CO2 emitted is that which was absorbed from the atmosphere during the growth of the original plant biomass. This means that incinerating bioplastics results in a much lower net gain in atmospheric CO2, than burning fossil plastic.

So for a lower environmental impact, drop-in, biodegradable and compostable bio-plastics are head and shoulders above conventional plastics. 

 There is still time to sign the petition to ban all non-recyclable/non-compostable packaging in the UK, which is open to British citizens and UK residents: https://petition.parliament.uk/petitions/167596

Published: 21 February 17

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