On January 7, the phthalic anhydride market in Shandong exhibited a strong consolidation trend. The mainstream negotiated prices for ortho-xylene-based phthalic anhydride were between 5,900 and 6,150 yuan per ton, while naphthalene-based phthalic anhydride was quoted between 5,600 and 5,850 yuan per ton. The price of raw material ortho-xylene fluctuated upward, while industrial naphthalene prices remained stable, leading to an increase in phthalic anhydride production costs. Downstream plasticizer prices surged strongly, and phthalic anhydride plant operations declined, resulting in reduced operating rates among producers. Despite ample market supply, the operating load of plasticizer enterprises decreased. However, rigid demand for phthalic anhydride persisted, supporting expectations of a strong upward trend in the phthalic anhydride market outlook.