This standard specifies the method for determining the saponification value and ester content of plasticizers, particularly applicable to common plasticizers such as phthalates. The core method is the saponification-titration technique, which involves saponifying the esters in the sample using a potassium hydroxide-ethanol solution, followed by titrating the excess alkali with a standard acid solution. This method integrates and improves upon previous versions, and its calculation results are applicable to all plasticizers, providing a unified basis for production quality control and product evaluation. The equipment required for the determination process includes ground-neck conical flasks and reflux condensation devices. In modern laboratories, automated instruments such as potentiometric titrators are also commonly used for such analyses to enhance the accuracy and efficiency of the results.