Potential Pollution by Biodegradable Waste: Assessing the Degradability of Oxo-degradable, Compostable, and Biodegradable Products Under Laboratory Conditions

This study evaluated the degradability of three products, namely an oxo-degradable garbage bag (GB), compostable lunch sheet (LS), and biodegradable salad plate (SP), under four controlled laboratory simulations representing natural environmental conditions: freshwater body (FW), riverbank (RS), landfill (COM), and direct ultraviolet (UV) light exposure. Degradation was assessed over time by monitoring the monthly changes in weight. Mechanical and chemical changes were monitored using tensile strength testing and Fourier-transform infrared (FT-IR) spectroscopy, respectively. Among the tested products, SP exhibited the highest mean percentage weight loss (43.76±3.34 to 100%) under RS conditions. Instead of weakening, GB exhibited increased mean tensile strength at break and mean elongation at break under RS (7.25±0.29 and 317.78±9.15, respectively) and COM (4.35±0.88 and 46.16±28.11, respectively), suggesting possible crosslinking or physical aging rather than degradation. No loss of characteristic peaks indicating biodegradation of the polymer material was observed in SP under FW and UV exposure, LS under UV exposure, and GB under FW, RS, or COM exposure. The findings highlight that degradation rates vary substantially across different environmental media and sample types. The potential contribution of certain biodegradable materials, particularly oxo low-density polyethylene (oxo-LDPE), to long-term plastic pollution is emphasized in this study.