Diisobutyl Phthalate (DIBP) is prepared by esterification process of isobutanol and phthalic anhydride. Its structural formula is C6H4(COOCH2CH(CH3)2)2. Refractive index is 1.488 - 1.492 (20 °C, D). DIBP is an odorless plasticizer and has excellent heat and light stability. It is the lowest cost plasticizer for cellulose nitrate. DIBP has lower density and freezing point than DBP (dibutyl phthalate, CAS No.: 84-74-2). It has similar properties as dibutyl phthalate and can be used as a substitute for it. DIBP is used in nitro cellulose plastic, nail polish, explosive material, lacquer manufacturing and used with methyl methacrylate applications. The concentration of a metabolite of DIBP (Mono-isobutyl phthalate or MIBP) has been steadily increasing in the urine of Americans over the period 1999-2008. Prenatal maternal exposure is associated with substantial harm to intellectual development in children.