Impacts of single use bioplastics

December 2019: Swapping conventional plastics for bioplastics may have adverse effects on waste generation and further incentivise a culture of single use. Instead, new research recommends to rather reduce the general consumption of plastics and to only substitute plastic for bioplastics in food packaging. This could generate a waste stream that does not contribute to landfills and reduces the amount of non-recyclable plastics due to food contamination.

Information

A new study projects that global demand for plastic products will increase by 22% over the next five years and will represent 17% of the global carbon budget by 2050. However, increasing awareness of plastic pollution has driven consumer demand for alternative plastics such as compostable bioplastics. Bioplastics are derived from plant matter – such as starch and polylactic acid - that can be broken down in an industrial setting by microbes into organic matter, making the material itself carbon-neutral. The study finds that direct replacements of plastics with bioplastics may be harmful for the environment. It may perpetuate a single use culture, since it is predicated on disposal to landfill or industrial composting rather than recycling or reuse. It can also confuse consumers who may place bioplastics in recycling bins, thereby contaminating recyclable plastic.

Implications & Opportunities

The researchers find that compostable bioplastics are only compostable in an industrial setting and that the general waste management infrastructure it is not yet in place, leading to many bioplastics being incinerated or deposited in landfills. In addition, the coating used in bioplastics to repel water and oil may leach into the compost and potential health impacts of applying this material to crops have not yet been explored. Instead, the researchers advocate for a general reduction of plastic consumption across all levels. Nonetheless, using bioplastics for food packaging – such as sandwiches – could reduce the amount of plastics in landfills that cannot be recycled because of food contamination. Such packaging could be industrially composted with other food wastes and strengthen waste streams away from landfills.

Limitations

Research on bioplastics and their compost remains at very early stages and all recommendations should be seen as indicative. Full lifecycle assessments are needed to properly compare competing alternatives w.r.t. their energy and resource requirements.

Sources

Sangwon Suh, J., (2019). Strategies to reduce the global carbon footprint of plastics. Nature Climate Change. DOI: 10.1038/s41558-019-0459-z

BBC. (2019). Why biodegradables won’t solve the plastic crisis. Retrieved from https://www.bbc.com/future/article/20191030-why-biodegradables-wont-solve-the-plastic-crisis