Researchers in Japan have developed a novel plastic that completely dissolves in seawater within a matter of days, offering a potential breakthrough in the global fight against ocean pollution. The innovation comes from a collaboration between the RIKEN research institute and the University of Tokyo.

Designed to degrade

The new material, known as D-MPL, is a form of polyester that is both recyclable and fully biodegradable in marine environments. In contrast to conventional plastics, which can linger for decades and break down into harmful microplastics, this plastic degrades into harmless components, such as succinic acid and other water-soluble compounds.

Lab tests showed that thin films of the plastic dissolved in seawater in under a week at 30°C. Even at lower temperatures (15°C), degradation occurred within a month. According to the research team, the process leaves no microplastics behind.

Tackling plastic pollution

Global plastic production exceeds 400 million tonnes per year, with an estimated 11 million tonnes ending up in the ocean annually. Materials that break down safely in seawater could help reduce the long-term environmental footprint of plastic waste, particularly in coastal and marine settings.

Researchers caution, however, that this is not a licence to litter. The plastic is intended for use in applications where marine exposure is likely or unavoidable—for example, fishing gear, shipping labels, and marine packaging.