The present invention relates to the use of a depleted epoxidized fatty acid ester mixture as plasticizer in a halogenated resin composition, said ester being obtainable by a process comprising epoxidation of a vegetable oil, transesterification of the epoxidized vegetable oil, short path distillation of the trans-esterified epoxidized vegetable oil and selection of the non-vaporized fraction of the preceding process step. The depleted ester mixture is suitable for being incorporated in halogenated resin compositions at a ratio exceeding 40 phr, without causing rheological or other problems to occur under practical industrial applications for the plasticized resin composition.