The environmental impact of plastics has long been a global concern. Pollution from mismanaged waste poses significant risks to ecosystems. It affects food and water safety, is a massive economic burden and significantly contributes to climate change. In 2019 alone, around 20 million metric tons of macroplastic (pieces larger than 0.5 mm) were leaked into the environment. Once there, such materials can persist for centuries. And, that figure doesn’t include the unknown volume of microplastic pollution.
A recent study has presented an innovative solution to this vast and complicated issue: foamed biodegradable bioplastics. The cellulose diacetate (CDA) foams are a promising alternative for Styrofoam products and single-use plastics. They’re strong and durable like regular plastic, but break down in saltwater significantly faster.
Plastic is one of the planet’s most persistent problems
Plastic foams, such as polystyrene, are widely used in food packaging and insulation. Lightweight, cost-effective and thermally efficient, these materials are however notoriously difficult to recycle and often escape waste management systems. In 2022, plastic foam takeaway containers ranked among the most commonly found items during global beach clean-ups. The very properties that make them so useful also mean that they stick around in the environment for decades or centuries after their often one-time use.
Scientists have been redesigning plastic products to minimise their environmental footprint for years. However, when Bryan D. James and colleagues investigated whether adding small pores to CDA material would maintain material efficiency while simultaneously accelerating degradation. Even they were surprised by the outcome. This process made the plastic degrade 15 times faster than solid CDA, even faster than paper. Whereas polystyrene showed no measurable degradation at all in a marine environment after 36 weeks, CDA foams lost 65–70 percent of their mass during the same timeframe.
Or, put another way, while a 1 mm-thick solid CDA film might take 15–20 years to degrade in the ocean, a low-density foam of the same thickness could biodegrade in under a year.
Are foamed bioplastics a catch-all solution?
However, the transition to foamed bioplastics is not without its challenges. Ensuring that bioplastics are disposed of in environments where they can degrade, such as industrial composting facilities, remains a hurdle. In most regions, infrastructure for managing biodegradable waste is limited. Likewise, contamination from mixed materials could currently further complicate disposal.
As of 2024, foamed bioplastics in the form of CDA products have begun entering the market. The first product to hit the shelves is a lightweight, foamed CDA tray which mimics the plastic trays currently used in industrial food packaging. However, the study cautions against viewing such biodegradable bioplastic products as a panacea. While foamed CDA does represent a substantial improvement, it doesn’t eliminate the challenges associated with packaging disposal. However, the environmental and economic benefits of switching to biodegradable foams are certainly compelling. The researchers estimate that using CDA foams in food packaging could save societies billions of euros annually by reducing the costs of ecosystem damage, loss of tourism revenue and expenses associated with clean-up efforts.
It’s clear that we must be looking further than a magic button to get us out of the mess of plastic pollution. Whilst such developments in technology present a step in the right direction, what our planet needs is a holistic approach. Technological advances, improved waste management infrastructure, as well as public education must all be incorporated. Only then can we comprehensively address the global plastic crisis and provide a greener planet for future generations.
