Dioctyl phthalate (DOP) is the most common plasticizer of the phthalate family and is still used as one of the main, most widely used, and cheapest softeners of polyvinyl chloride in the plastic industry in the world. This oil is the result of esterification. Phthalic anhydride and diethylhexanol alcohol. It is a transparent oily liquid, insoluble in water, odorless, with high thermal stability and resistant to UV rays. Khorram Plastic Company, as one of the largest producers of this oil, and by using modern technology and expert staff, has been able to make an important contribution to the domestic production of this product with an annual production capacity of 12,000 tons.