Bioabsorbable Characteristics of Poly (Lactic Acid) (PLA) for a Fundamental Solution to the Problem of Microplastics Tea Bag SOILON<sup>® </sup>Made from PLA Fibers

The aim of this research was to solve the problems of accidental ingestion of microplastics such as in case of tea bag filter, in addition to the solid wastes management of food packaging plastics after use. PLA was not only aerobic compostable but also anerobic digested to biogas by methane fermentation at 50°C after a month, similar to that in composting at 60°C. Also, PLA was hydrolytic degraded in physiological saline solution at 37°C, that is the simulated condition of human body. Due to the relative slow degradation rate of PLA, its medical applications have been mainly to bone-fixation, taking about three months. The degradation of PLA in the human body by hydrolytic scission of ester linkage yielded lactic acid which was a naturally occurring acid without ill effects. It was suggested that PLA would remain temporarily in the body and disappear upon biodegradation followed by bioabsorption.