Odor Modification in Rigid Polyethylene Waste: Impact of Different Washing on Sensory Analysis and Characterization

ABSTRACT Persistent odor in recycled polyethylene (PE) limits its use in high‐demand applications, necessitating effective deodorization. We investigated how washing affects the odor profile and intensity of post‐consumer rigid PE, using sensory analysis, comparative odor extract dilution analysis (cOEDA), and two‐dimensional gas chromatography‐mass spectrometry/olfactometry (2D‐GC‐MS/O). Three methods were evaluated, varying in temperature and surfactant use: room temperature water (RT, 25°C), hot water (HW, 80°C), and detergent with caustic soda (DW). Sensory analysis showed that no treatment significantly reduced overall odor intensity or hedonic ratings, although washing modified the qualitative odor profile. Median values indicated a modest downward trend for DW (17% reduction), though not statistically significant. cOEDA and 2D‐GC‐MS/O results aligned with these qualitative shifts, including reduced moldy and increased soapy and flowery notes. Of 32 odor‐active compounds detected in post‐consumer rigid PE, 28 were identified. Rose oxide, dihydromyrcenol, hexyl salicylate, and α‐hexylcinnamaldehyde are reported for the first time in post‐consumer PE. This study deepens understanding of post‐consumer PE odor and highlights challenges in developing advanced deodorization techniques for the circular economy.