On January 15, the phthalic anhydride market in Shandong region showed a strong consolidation trend. The mainstream negotiated price for phthalic anhydride produced via the ortho-xylene method ranged from 6,100 to 6,350 yuan/ton, while the mainstream negotiated price for phthalic anhydride produced via the naphthalene method ranged from 5,700 to 6,050 yuan/ton. The price of raw material ortho-xylene fluctuated and rose, while the price of industrial naphthalene stabilized. The cost of phthalic anhydride increased, and the downstream plasticizer market experienced a strong upward trend. The operating rates of phthalic anhydride production equipment declined, leading to a decrease in the overall operating rate of phthalic anhydride enterprises. The supply in the phthalic anhydride market remained ample, while the operating load of plasticizer enterprises remained stable. The demand for phthalic anhydride continued to provide support, and the market outlook is expected to remain strong with consolidation.