The main dissolved compounds from the DOTP production unit are dioctyl terephthalate and alcohols - isopropanol and 2-ethylhexanol. In the course of operation of the neutralization and treatment unit of industrial wastewater of Sibur-Khimprom JSC, the oppressive effect of DOTP unit wastewater on the operation of the biological treatment unit was revealed. Additional research and analysis of the biological treatment unit operation data confirms the pronounced toxicity of DOTP effluent.