Bioplastics - biodegradable or nah?

What does the future hold for the plastic problem? The idea of bioplastics, or biodegradable plastics is becoming more and more popular, but what do these terms actually mean?

My own understanding of it before I researched was that these plastics will degrade in the environment into a harmless solution – almost like a compost. However, it seems it isn’t that simple. By definition, biodegradable means ‘(of a substance or object) capable of being decomposed by bacteria or other living organisms and thereby avoiding pollution’ (Google definition as of 2016). Can bioplastics achieve this?

Manufactured bioplastics come under two main categories; 1) those which are created from renewable resources (bio-based), and 2) those which are compostable (but based on either renewable OR fossil resources). This lack of attention to detail when it comes to the increased use of bioplastics is quite important, especially when they are being marketed as the solution. With many governments taking new measures to divert waste from landfill, the market share of bioplastics is increasing from less than 1% to an expected 10% of plastic consumption. As a result, more research needs to be focused on the legitimacy of bioplastics as a solution.

The basis behind bioplastics would be the Life Cycle Assessment (LCA) – a new mode of production which is designed with the products end of life in mind. This approach has the potential to limit pollution, limit our carbon footprints, but also to increase the responsibility of both producers and consumers toward the environment.

Nonetheless, a new mode of waste is not easily implemented. Even with relatively new materials such as microbeads, infrastructure (particular that of waste water treatment plants) are inept at filtering the particles. The same goes for bioplastics – a whole set of supporting policy and infrastructure will have to be designed to accommodate the wider spread use. And that takes time. Not only do waste management infrastructures need to be equipped, but to encourage the growth of the industry would require support from the public and the state, including subsidies for manufacture. While bio-fuels already receive this type of support, bio-based plastics remain under-represented, making competition with their oil-derived counterparts difficult.

Is it such a bad thing that they haven't made it big yet? The LCA of bioplastics is still largely uncertain. The EU Directive categorises landfill as the least desired option for waste, and puts forward four other options instead: 1) Reduce, 2) Reuse, 3) Recycle or compost, and 4) Recovery (such as waste-to-energy incineration). Concerning the third option however, the EN13432 standards to which compostability is tested is done so mimicking conditions within an industrial composter. But will bioplastics that end up in the natural environments (terrestrial, riverine, or marine) be composted to the same standard and extent?  

Further issues taken up with bioplastics is their compatibility within recycling industries. Biodegradable plastics can reduce the quality and longevity of recycled goods, undermining the functioning performance of the finished product. This is because the natural fibres degrade over time. The other problem with recycling is the complex array of materials entering the stream, and the lack of easy distinction between these materials, complicating the quality control.

A study of the LCA for biodegradable plastic packaging found that both landfill and industrial composting generated higher environmental impacts than other options. This is in contrast to the reinforced notion that bioplastics are suitable for composting – it ignores the range of issues such as the low NPK (nitrogen, phosphorous, potassium) of bioplastics, which therefore renders them almost useless to compost quality and energy recovery as fertilisers. Likewise, in conditions outside of a controlled industrial composter, such as landfill or even domestic composters, poorly regulated systems can reduce effective degradation, and generate methane instead.

I would say the factor contributing most to my caution regarding bioplastics is the lack of public awareness of the distinctions between the different types. When bioplastics are advertised as a unified alternative to regular plastics or even other materials, it is misleading. The whole term ‘biodegradable’ makes people think of the process an apple undergoes when you throw it into a bush – it breaks down into nothing, and effectively disappears. But without the correct infrastructures in place, bioplastics will not just disappear in the environment. Bioplastics currently do not seem like a viable solution. For me, the ultimate ‘win’ would be reducing at the source. Let’s go minimalistic – less consumption, less packaging, less unnecessary waste. To roll out bioplastics without first ensuring an environmentally friendly LCA, and without adequate supporting infrastructures would only be a very temporary fix to a continuous problem.