Some aspects of the state of the problem of using diester phthalate plasticizers for polyvinyl chloride plastic compounds are considered. The effect of the plasticizer dioctyl terephthalate on the rate of thermo-oxidative dehydrochlorination of polyvinyl chloride (PVC) has been studied. It has been established that dioctyl terephthalate has a higher thermal and oxidative stability and has a lesser effect on the thermal oxidative degradation of polyvinyl chloride (PVC), in comparison with the plasticizer dioctyl phthalate, which is widely used in the production of PVC. The influence of non-toxic antioxidants - 2,6-di-tert-butyl-4-methyl-phenol (ionol), 4-hydroxy-3.5-di-tert-butylphenylpropionic acid ester (irganox 1010) on the process of accumulation of hydroperoxides and effective dosages of antioxidants were selected to inhibit the process of thermal-oxidative degradation of the polymer. The possibility of complete replacement of the toxic plasticizer dioctyl phthalate with non-toxic dioctyl terephthalate is shown. The use of dioctyl terephthalate stabilized with antioxidants is appropriate to increase the thermal stability and durability of PVC compounds.