Writing

The Reality of Bioplastics

July 6, 2026The science behind bioplastics works, but scaling them to compete with cheap petroleum plastic is the ultimate engineering hurdle.

When walking down a supermarket aisle, there's an abundance of products labelled as “100% biodegradable”, “compostable”, or “made from plants”. It’s easy to think that these products are equally good for the environment, but I’ve always been a bit suspicious and wanted to investigate them further.

Firstly, I was shocked to see there was a stark difference between the terms “biodegradable” and “compostable”.

  • Biodegradable is an umbrella term describing anything that breaks down naturally over an undefined period of time.
  • Compostable is a strict engineering term referring to a material that breaks down into water, carbon dioxide, and biomass (all are non-toxic) under specific timeframes.

So if a product takes 100 years to break down in the presence of microbes, and leaves behind toxic residues and harmful microplastics, it can still be called “biodegradable”. At this point in my research, I had a mini-crisis, trying to recall whether products I had purchased in the past were explicitly labelled as “compostable”.

For instance, one of the most common bioplastics is PLA (Polylactic Acid), which I recognised immediately from 3D printing. It is commonly used in eco-friendly packaging, like disposable cutlery. Although it is technically biodegradable, it takes over 180 days to break down in industrial settings requiring high temperatures, moisture, and specific enzymes. If it ends up in a landfill or ocean, it’s pretty much just as bad as regular old petroleum-based plastic. Overall, only a tiny fraction of consumer PLA is recycled.

The current issue

This highlights the massive systemic failures of our current recycling infrastructure:

  • Contamination: Different bioplastics require completely different processing methods. Sorting them requires advanced optical scanners, time, and labour. For example, if there is a small amount of PLA in a batch of PET (polyethylene terephthalate, which is what plastic bottles are normally made of) and you tried to recycle it, the PLA would weaken the entire batch of recycled plastic and release toxic chemicals.
  • Facilities: Most local waste systems simply do not have the industrial facilities required to break down PLA, meaning the vast majority of these "green" plastics end up buried in landfills anyway.

As a result, only 5-6% of consumer plastic in the US is actually recycled. This statistic really shocked me.

The cutting edge

An amazing development in compostable plastics is PHAs (Polyhydroxyalkanoates, I dare you to try to pronounce it). PHAs are polyesters naturally produced by microbes as energy storage (it’s like “bacterial fat”). As a natural polymer, it is 100% compostable, breaking down naturally in soil and marine environments. Pioneers like Kaneka and PhaBuilder are aggressively scaling up bacterial fermentation production to bring PHAs to packaging, cosmetics, and biomedical applications.

Similarly, a UK start-up called Notpla has developed a proprietary seaweed-based packaging that completely decomposes into non-toxic byproducts in about 6 weeks, which is pretty much how long fruit takes to break down.

The reality

So why do we still rely on petroleum plastics?

These exciting new compostable materials come at a premium price to consumers. Notpla will rightfully point out that there are “shadow costs” of plastic: the hidden environmental, health and economic costs of plastic over its lifecycle. They estimate that the hidden cost of plastic is ten times its market value.

Although this is very true, many consumers and companies care more about the face value of materials, therefore avoiding costly compostable choices. Still, sustainability is only sexy when it doesn’t cost too much.

The problem of scale

In my opinion, this highlights a common problem in sustainability technology. We aren’t suffering from a lack of amazing technologies; startups and labs around the world are showing that scientific innovation isn’t the problem. Instead, it is a scalability problem.

Traditional plastic production has had a massive head start in manufacturing efficiency and supply chain optimisation. Simply put, it’s ridiculously cheap to make plastic. The next step, instead of developing the next cool polymer, is building industrial fermentation and chemical processing at scale to make seaweed-based packaging just as cheap as plastic packaging.

Some potential opportunities I see are:

  • Focusing on designing alternative biomaterials that work with as much of the existing manufacturing infrastructure. It would be great if you could use the same injection moulding equipment and moulds.
  • Invest in large-scale facilities to continuously produce biopolymers to benefit from economies of scale.
  • Investigate cheaper material costs. For instance, using food and heat waste from other manufacturing facilities to feed and heat the bacteria that make PHAs.

How can we use these groundbreaking technologies in everyday products at scale in a way that is affordable and accessible?

Sources & References