Creating Ocean-Safe Plastic from Seashells

Researchers at USC Viterbi School of Engineering have developed a new biodegradable plastic substitute that could help reduce marine pollution. Led by Dr. Eun Ji Chung, the team used calcium carbonate — a mineral found in seashells — and combined it with poly (1,8-octanediol-co-citrate) (POC), a biocompatible polymer approved by the FDA. This innovative material, dubbed POC-CC, mimics the properties of traditional plastics while offering the added benefit of breaking down in marine environments without producing harmful microplastics.

As reported by Greta Harrison, the inspiration for the project stemmed from Chung’s growing concern about plastic waste during the COVID-19 pandemic, particularly from sterile single-use lab materials. Drawing on her earlier research with citric acid-based biodegradable polymers, Chung realized she could adapt this technology for more sustainable, environmentally friendly applications. By incorporating calcium particles derived from seashells and heating the mixture, the team produced a sturdy prototype — including soda can rings — capable of replacing traditional petroleum-based plastics.

Testing revealed that the material safely degrades in ocean water over time, does not alter pH levels, and remains non-toxic to marine life such as green algae. Supported by a USC Sea Grant, the project emphasizes the importance of sustainable innovation along urban coastlines. Chung’s lab now plans to refine the material further for faster degradation and expand its use to other everyday products like stronger, eco-friendly straws — potentially reshaping how we think about plastic and its environmental legacy.