Bis(2-ethylhexyl) phthalate (di-2-ethylhexyl phthalate, diethylhexyl phthalate, DEHP; dioctyl phthalate, DOP), is an organic compound with the formula C6H4(C8H17COO)2. DEHP is the most common of the class of phthalates which are used as plasticizers, accounting for an almost 54% market share in 2010. It is the diester of phthalic acid and the branched-chain 2-ethylhexanol. This colorless viscous liquid is soluble in oil, but not in water. DEHP is a High Production Volume Chemical.