This project assessed biodegradable alternatives to polyethylene (PE) for bain-marie liners by comparing PLA and PBS with conventional PE under 80 °C wet-heat conditions. While PLA and PBS show higher strength, both lack the flexibility and durability required. PLA softens and becomes brittle, and PBS shows reduced ductility after heat exposure. PE remains the only material that maintains performance. Modified or blended biopolymers are identified as the most promising route for sustainable alternatives.