In 2025, the price of isooctanol experienced a volatile decline. According to the commodity market analysis system of Business Society, as of December 31, the quoted price of isooctanol was 6,916.67 yuan per ton, representing a volatile decrease of 8.99% compared to the price of 7,600 yuan per ton on January 1. The average price of isooctanol in 2025 was 7,249.70 yuan per ton, a decrease of 26.69% compared to the average price of 9,889.58 yuan per ton in 2024, marking a five-year low. Factors such as overcapacity in the isooctanol industry, weak downstream demand, and insufficient cost support collectively contributed to a period of deep adjustment in isooctanol prices in 2025. **Analysis of Isooctanol Price Trends in 2025** **Phase 1: January–February – High-Price Consolidation** During the New Year and Spring Festival holidays, post-holiday restocking led to a slight volatile increase in prices. **Phase 2: March–April – Volatile Decline** The off-season for demand, coupled with reduced operating rates at isooctanol plants and declining raw material prices, resulted in a volatile decline in isooctanol prices. **Phase 3: May–July – Volatile Consolidation** Overcapacity in the isooctanol industry, combined with maintenance shutdowns at companies such as Luxi Chemical and Hualu Hengsheng, reduced operating rates to around 80%. This tightening of supply led to volatile price consolidation. **Phase 4: August–October – Rapid Decline** Persistent overcapacity, coupled with operating rates rising to as high as 95%, caused a sharp decline in isooctanol prices, reaching the lowest level since May 2020. **Phase 5: November–December – Rebound and Increase** Operating rates at isooctanol plants dropped to around 70%, leading to insufficient supply and a rebound in prices. **Supply Side: Capacity Expansion and Declining Operating Rates** In 2025, China’s total isooctanol production capacity reached approximately 3.8 million tons per year, with an additional 500,000 tons of new capacity added. Major expansions included projects by leading companies such as Luxi Chemical (500,000 tons) and Wanhua Chemical (300,000 tons). Operating rates fluctuated between 60% and 95% throughout the year, dropping to around 60% in April and rebounding to 90% from August to October. The overall operating rate remained below 80%, indicating a general oversupply of isooctanol. **Demand Side: Weak Downstream Demand and Accelerated Substitution** Over 90% of isooctanol demand comes from the plasticizer industry, with DOP accounting for approximately 70% and environmentally friendly plasticizers such as DOTP making up around 20%. In 2025, operating rates at DOP plants fluctuated between 40% and 65%. Weak demand for PVC products due to a sluggish real estate market led to minimal procurement of isooctanol, with inventories maintained at low levels. Stricter environmental policies accelerated the substitution of DOP with environmentally friendly plasticizers like DOTP, further weakening demand for isooctanol. **Raw Material Propylene Prices Volatile Decline, Reducing Isooctanol Costs** According to the commodity market analysis system of Business Society, as of December 31, the price of propylene was 5,717.67 yuan per ton, a volatile decrease of 16.36% compared to the price of 6,835.75 yuan per ton on January 1. The decline in propylene prices reduced the cost of isooctanol, weakening cost support and increasing downward pressure on isooctanol prices. For most of 2025, isooctanol production operated at minimal profits or losses. In October, prices fell below the cost line, resulting in slight losses. However, profits recovered in December as prices rebounded. **Market Overview and Outlook** Business Society’s isooctanol product data analyst believes that, in the short term, factors such as post-Spring Festival restocking, new production capacity, and reduced operating rates will tighten isooctanol supply in the first quarter of 2026. Additionally, rising propylene prices will strengthen cost support, leading to a volatile increase in isooctanol prices during this period. In the long term, the commissioning of new production capacity and the accelerated exit of outdated capacity due to industry consolidation may sustain an oversupply situation. As a result, isooctanol prices are expected to remain low and consolidate.