Towards a more environmentally friendly expanded polystyrene fish box: A structurally and thermally validated lightweight design with life cycle assessment

Expanded polystyrene (EPS) fish boxes are widely used in seafood logistics owing to their lightweight structure and superior insulation performance. However, their high material consumption and end-of-life challenges raise increasing environmental concerns. This study presents a systematic approach to developing a more environmentally friendly EPS fish box through a thermally and structurally validated lightweight design combined with a life cycle assessment (LCA). Parametric and non-parametric sensitivity analyses were performed to quantify the influence of wall thicknesses, box height and corner radii on the mechanical response. Based on the sensitivity results, targeted lightweight configurations were proposed and experimentally validated with respect to stacking strength and thermal insulation performance. The validated design achieved up to 11% weight reduction without compromising structural integrity and only reduced insulation performance by 9% in ice-melting experiment and 6% in temperature-rise regression analysis. Corner ice in the lightweight design was found to have enhanced the thermal insulation. The subsequent LCA on the EPS box production and transport confirmed that plastic reduction leads to a proportional decrease in environmental impacts across all impact categories. This integrated analysis-design–validation–assessment framework demonstrates a practical route for reducing material use and environmental burden in EPS packaging while maintaining essential functional performance. • Integrated lightweight design framework combining sensitivity analysis, experimental validation, and LCA. • Achieved 11% weight reduction while maintaining stacking strength. • Thermal insulation only slightly reduced (9% ice-melting; 6% temperature-rise). • Lumped capacitance method validated through agreement of R-values from two thermal tests. • Environmental impacts reduced across all categories, including 10%–11% lower global warming potential.