China's Switch to Biodegradable Plastics Won't Solve the Pollution Problem

It has been nearly a year since the Chinese government banned several kinds of single-use plastics in an effort to curb pollution. The ban takes effect in large cities by the end of this year and will be nationwide by 2025. In response, many companies have switched to the production of biodegradable plastics. While this may seem like a logical step to take, a new report by Greenpeace reveals that biodegradable plastics are far from being an ideal solution to the problem.

It's helpful to realize just how rapid the expansion of biodegradable plastic production has been. Greenpeace reports that, in China, 36 companies have "planned or constructed new biodegradable plastic projects, with an added capacity of more than 4.4 million tonnes, a sevenfold increase since 2019." It's estimated that a cumulative amount of 22 million tonnes of biodegradable plastics will be needed over the next five years in order to replace the conventional single-use plastics that have been banned in China. Global demand is expected to rise to 550,000 million tonnes by 2023. This is production on a massive scale, but unfortunately misguided.

There are three main concerns about biodegradable plastics, according to Greenpeace. The first is feedstocks, and where these are sourced. When biodegradable plastic is made, it contains agricultural products such as corn, potato, cassava, and sugar cane. Rising demand for these feedstocks could lead to deforestation in the same way that palm oil and soy expansion have decimated forests in the Global South. It could create competition within food supply chains and put pressure on water supplies, potentially worsening hunger in developing nations. Few biodegradable plastic producers reveal the source of their feedstocks and there is no international requirement to adhere to responsible or sustainable sourcing. 

A second big concern is potential health risks coming from the additives and plasticizers used in the manufacturing process. From the Greenpeace report:

"A recent study analyzing bio-based and/or biodegradable plastic products in the European market found that 80% of tested products contained more than 1,000 chemicals, and 67% of tested products contained hazardous chemicals."

PFAS (per-/poly fluoroalkyl substances) are one example of chemicals used to impart grease and water resistance. Some PFAS are known to be carcinogenic and persistent in the natural environment. It's unclear if the hazardous chemicals can enter products put inside biodegradable plastic packaging, but there is real concern about them entering compost when the plastic is biodegraded at the end of its life cycle.

Finally, there is the issue of inadequate disposal facilities that ensure biodegradable plastics actually do break down once discarded. Biodegradable plastics do not have consistent labeling standards and can contain various components, all of which require different conditions for full breakdown. Product descriptions are often lacking or even misleading or false. 

Many kinds of biodegradable plastics require tightly-controlled industrial conditions, but proper facilities are few and far between. From the report: "[A] 2019 statistic suggests that only seven countries among the 21 European countries have enough composting facilities to treat all organic waste generated within the country. Composting capacity is even more scarce in the US and China, representing 3% and 4% of entire waste disposal capacity, respectively."

Even when industrial composting facilities are available, they don't want biodegradable plastics. This is because kitchen waste breaks down within six weeks, but plastic requires longer, which creates an awkward time discrepancy. Compostable plastics are hard to distinguish from conventional plastics, so there's a fear of mixing happening, resulting in contamination. Breaking down plastic adds no value to the resulting compost, and if anything fails to degrade fully it is treated as a contaminant.

Furthermore, the laboratory conditions in which biodegradable plastics are tested cannot always be replicated in the real world. Claims of being marine-degradable, soil-degradable, freshwater-degradable, etc. are continuously proven to be inaccurate. As the report explains, these claims "cannot answer the question that everyone is eager to know: 'Can this biodegradable plastic I bought really biodegrade in my town?'"

Greenpeace USA Oceans Campaign Director John Hocevar told Treehugger:

"Concerns around biodegradable plastics are emerging around the world as companies scramble to find solutions to the plastic pollution crisis. Unfortunately, it is not the quick fix that corporations are looking for. Many biodegradable plastics require very specific conditions to break down and can still end up polluting our environment just as fossil fuel plastics do. It is time for companies to stop swapping out one throwaway material for another and move toward systems of reuse to tackle this crisis." 

So, if biodegradable plastics are not going to solve the pollution crisis, what will? 

The report authors call for a greater push by government for an overall reduction in single-use plastic usage and an increase in reusable packaging systems, combined with the expansion of "extended producer responsibility" (EPR) schemes that hold manufacturers accountable for dealing with the consequences of their own poor design decisions, a.k.a. superfluous waste. 

None of this will be easy to achieve, as it requires more complete behavioral shifts than simply producing biodegradable plastics and allowing consumption habits to continue, but it's crucial if we hope to deal with this problem in a thorough and lasting way. (As Lloyd Alter has written for Treehugger in the past, "To get to a circular economy, we have to change not just the [disposable coffee] cup, but the culture.") Hopefully, the Greenpeace report will spur the Chinese government to rethink its strategy and compel other leaders around the world to take note and develop progressive waste-reduction strategies of their own.