Expanded polystyrene (EPS), commonly used as a cooler box for fish storage, has become a major contributor to marine plastic pollution. Its non-biodegradable nature and tendency to fragment into microplastics threaten aquatic ecosystems and food safety. To address this issue, we propose the Bio Think Cooling Box, an eco-friendly multilayer cooling box composed of bio rigid polyurethane foam derived from castor oil and a cassava starch-based bioplastic coating. The rigid foam provides thermal ins