According to the Business Society Commodity Market Analysis System, the price of plasticizer DOP stabilized initially and then declined in 2025. As of December 31, the DOP price was 7,325.84 yuan per ton, fluctuating downward from 8,226.25 yuan per ton on January 1, representing a decrease of 10.95%. In 2025, the price of isooctanol also stabilized initially before declining, with a slight rebound toward the end of the year. The overall annual price level was significantly lower compared to 2024.

Supply Side: Overcapacity and Low Operating Rates
In 2025, the total domestic DOP production capacity was approximately 2.5 million tons per year. While new capacity was added during the year, some existing capacity was also phased out. The new capacity was primarily concentrated in expansion projects by leading enterprises. The operating rates of DOP plants fluctuated between 40% and 70% throughout the year, with an overall rate below 60%. The DOP industry faced overcapacity, and operating rates remained low and range-bound.

Cost Side: Raw Material Prices Continued to Weaken
According to the Business Society Commodity Market Analysis System, as of December 31, the price of isooctanol was 6,916.67 yuan per ton, fluctuating downward from 7,600 yuan per ton on January 1, representing a decrease of 8.99%. The average price of isooctanol in 2025 was 7,249.70 yuan per ton, a 26.69% decline from the 2024 average of 9,889.58 yuan per ton, hitting a five-year low. Overcapacity in isooctanol, ample spot supply, and continuous price concessions by suppliers drove the decline in isooctanol prices, which became a major factor in reducing DOP production costs.

As of December 31, the price of phthalic anhydride was 5,966.67 yuan per ton, fluctuating downward from 6,600 yuan per ton on January 1, representing a decrease of 9.60%. Influenced by declining ortho-xylene prices and oversupply in the phthalic anhydride market, prices trended downward throughout the year, with a slight rebound in late December.

Future Outlook
Business Society plasticizer product data analysts believe that the fluctuating decline in raw material prices, including isooctanol and phthalic anhydride, led to lower DOP production costs, resulting in a downward price trend for DOP in 2025. Looking ahead, in the short term, restocking ahead of the Spring Festival and rising raw material prices are expected to drive a fluctuating increase in DOP prices in the first quarter of 2026. In the long term, limited new capacity additions on the supply side, coupled with potential marginal improvements in demand due to relaxed real estate policies, are expected to support a recovery in demand. As a result, DOP prices are projected to remain strong and range-bound in 2026.