The SCG-backed Long Son Petrochemical (LSP) complex in Vietnam fully resumed operations on August 20, 2026, it is reported. The complex had halted operations in May 2025 due to feedstock supply issues and restarted after roughly 10 months.
The Long Son Petrochemical complex, located in southern Vietnam, is the country’s first integrated petrochemical complex, producing base petrochemical feedstocks such as ethylene, propylene and butadiene from a naphtha cracker alongside polymer products including HDPE (high-density polyethylene), LLDPE (linear low-density polyethylene) and PP (polypropylene). The restart reportedly came against a backdrop of improved feedstock-to-product margins as international oil prices declined, following the extended shutdown driven by last year’s feedstock supply issues.
Total investment is reported at approximately $5.4 billion, with naphtha cracker capacity of 950,000 tonnes per year of ethylene, 400,000 t/y of propylene and 100,000 t/y of butadiene. On the polymer side, the complex has capacity of 500,000 t/y of HDPE, 500,000 t/y of LLDPE and 400,000 t/y of PP. The shutdown period ran from May 2025 to August 20, 2026, about 10 months.
The Long Son complex is a large-scale investment by SCG to expand its petrochemical business across Southeast Asia, and this restart is reportedly driven primarily by eased feedstock cost pressure as international oil prices declined.
This case, in which a large naphtha cracker complex halted operations for an extended period amid deteriorating feedstock supply conditions before restarting as market conditions improved, illustrates how sensitively petrochemical industry conditions respond to feedstock-to-product spreads. The roughly 10-month shutdown period in particular suggests that the persistent global petrochemical oversupply and margin deterioration of recent years directly affected even newly built complexes in Southeast Asia. The fact that this restart was triggered by lower feedstock costs following declining international oil prices shows that similar shutdown-and-restart cycles could recur at naphtha crackers elsewhere depending on future oil price movements. As Vietnam’s first integrated petrochemical complex, whether it operates stably has a direct bearing on Vietnam’s domestic polymer self-sufficiency and import substitution effects. Amid a broader trend of continued large-scale Thai corporate investment in Vietnam across Southeast Asia, this restart can also be seen as a sign that the long-term results of regional petrochemical investment are starting to materialize.
How far the complex’s actual utilization rate recovers after the restart, and whether stable operation continues, are the first points to confirm. Whether this restart proves sustainable depending on international oil and naphtha price trends, or whether operations could again be adjusted if market conditions worsen, is also worth watching. In addition, the impact of the Long Son complex’s full operation on Vietnam’s domestic polymer market and the regional polyethylene and polypropylene supply picture in Southeast Asia, as well as whether SCG pursues further investment in Vietnam, also bear watching.