A catalyst de-activator based on organic peroxides developed by Purac and AkzoNobel for the production of polylactic acid (PLA) plays an important role in controlling the polymerization by which PLA can be processed conveniently in standard, commercial polymer processing equipment. Under the new process, organic peroxides selectively switch off polymerization catalysts, improving the quality and stability of the PLA polymer. The result: A more stable PLA in melt processing with consistent flow properties while maintaining a positive environmental profile.