China’s SM Rewrites Trade Flows; Outages and Exports Drain Supply

China’s styrene monomer market tightened sharply in December, marking a decisive shift from the oversupplied conditions that had defined much of the second half of the year, as a combination of plant turnarounds, unexpected technical shutdowns and firm export demand reduced domestic availability and lifted prices from multi-year lows, according to market sources.

Supply losses inside China coincided with a surge in overseas buying for November through January loading, transforming the country from a market weighed down by excess stocks into a swing supplier for Asia, Europe and even India. Traders said the change in tone was abrupt, driven by both structural margin pressure and a growing list of offline units.

“December was when everything converged,” said a China-based SM trader. “Plants were already under margin stress, then outages kept extending, and exports suddenly became the pressure valve for the system.”

China’s SM exports rose about 40% month on month in November, according to Global Trade Tracker data, climbing to 23,688 metric tons from 16,930 mt in October. Most of the increase went to South Korea, a traditional outlet for Chinese SM, but a notable 7,400 mt was shipped to the Netherlands. The November cargo marked the first Chinese SM shipment to the European country since May, highlighting how sharply trade economics have shifted.

The export surge followed a steep decline in domestic prices earlier in November. Spot SM values in China weakened as oversupply emerged following maintenance at downstream derivative units, while demand slowed during the winter off-season. SM consumption deteriorated as polymer margins worsened and downstream producers reduced operating rates amid a seasonal lull.

“Downstream buyers were cutting runs, and SM was backing up in tanks,” said a China-based producer. “Margins were so bad that some SM plants had no incentive to keep running.”

Those falling prices ultimately reopened the arbitrage to Europe. According to OPIS monthly spot averages, Asia SM was assessed at $792.25/mt FOB China in November, compared with $890.50/mt CIF ARA in Europe. Freight from China to Europe was pegged in the low $100/mt range, leaving room for traders to move cargoes.

Once the window opened, fixtures followed quickly. A China-based trader said about 12,000 mt of SM was loaded in December for Europe, with another 6,000 mt fixed for January loading, all sourced from China. The arbitrage remained workable in December, even as prices rose on both sides. China’s FOB monthly spot average increased to $815.50/mt, while Europe CIF ARA climbed to $912/mt, according to OPIS data.

The revival of Chinese exports has been reinforced by limited supply from other traditional exporters. The U.S., typically a key supplier to the European market, has seen operating rates remain low. LyondellBasell has one propylene oxide/SM line with 1.4 million mt/year of SM capacity down for planned maintenance, with market participants saying the restart has been delayed into January, although this could not be confirmed. Westlake is in the process of permanently shutting its 633,000 mt/year SM facility, further reducing U.S. export availability.

As a result, the U.S. arbitrage window into Europe remains closed. Minimal loadings are likely to be fixed for January, following a similarly quiet December, keeping arrivals into Europe low in the coming weeks. While this supports operating rates for European domestic producers, margins remain challenging due to high costs and uneven demand, according to a CMA analyst.

“Without U.S. barrels, Europe has very little buffer,” said a China-based trader. “That’s why Chinese cargoes suddenly matter again.”

Supply from the Middle East has so far been steadier, but that consistency is expected to be tested in early 2026. Turnaround plans across the region are already influencing buying behavior and boosting interest in Chinese SM. Kuwait Styrene Company is scheduled to shut its 520,000 mt/year SM plant in Shuaiba, Ahmadi, in January for a two-month turnaround. Arabian Petrochemical Company, or Petrokemya, plans to take its 550,000 mt/year SM line in Al Jubail Industrial City offline in March.

“Middle East outages remove a lot of optional supply,” said a Singapore-based trader. “When you combine that with U.S. constraints, China becomes the fallback supplier for many buyers.”

China’s expanding export footprint was also evident in early January, when a 9,000 mt SM parcel was loaded for India. Direct exports from China to India are rare due to tariff barriers. Typically, South Korea exports its SM to India and then replenishes supply by purchasing material from mainland China. There was also spot buying interest from Turkey, a market traditionally covered by Middle Eastern and European material. Market participants said the unusual shipment underscores how tight regional balances have become and how export opportunities are helping to relieve surplus supply in China.

South Korea remains the single most important destination for Chinese SM. According to Global Trade Tracker data, South Korea’s SM imports rose to 58,551 mt in November from 45,955 mt in October. Japan accounted for about 33,000 mt, China supplied 14,857 mt and Taiwan, China contributed 10,694 mt.

The increase was largely driven by maintenance at Lotte Chemical Corp.’s 580,000 mt/year SM plant in Seosan, South Chungcheong, which was offline from October to November. A China-based trader said Korean demand for December and January loading has remained stable, with around 10,000–15,000 mt expected to be shipped from China to South Korea.

“Korea’s buying is very predictable, especially when plants are down,” the trader said. “China is the quickest and most flexible source.”

At home, China’s domestic SM market has shown clear signs of recovery after months of margin depression. Prolonged losses forced several SM producers to reduce operating rates, delay restarts or shut units altogether, easing the supply glut that had built up earlier in the year. The pickup in exports, combined with relatively stable downstream consumption, led to a steady drawdown in inventories.

Commercial SM inventories in East China fell from 192,500 mt at the end of October to 171,800 mt by the end of November and dropped further to 133,000 mt by the end of December, according to Chemical Market Analytics by OPIS data. Prices responded accordingly. The midpoint of OPIS ex-tank SM assessments sank to a four-year low of 6,290 yuan/mt on Nov. 11, before rebounding strongly to 6,860 yuan/mt by Dec. 26.

“The inventory numbers changed sentiment completely,” said a domestic trader. “Once stocks started falling, buyers stopped waiting and started covering.”

Supply constraints have been amplified by a long list of SM plant shutdowns across China. Anhui Jiaxi New Material’s 350,000 mt/year SM unit was offline from the second half of September through H1 December. Bright LyondellBasell Petrochemical shut its 350,000 mt/year SM plant for maintenance in December. New Solar Technology’s 300,000 mt/year SM unit has been down since late October, with restart timing still unclear.

Ningbo ZRCC LyondellBasell New Material’s 600,000 mt/year SM plant has been offline since late September, also with an undetermined restart. Satellite Chemical’s 600,000 mt/year SM unit was shut from H2 October to H1 December for maintenance. Sinochem Quanzhou Petrochemical brought forward maintenance at its 450,000 mt/year SM unit to mid-November after a fire at its No. 1 light hydrocarbon recovery unit, with operations expected to resume in mid-January.

More recently, China’s Tianjin Bohua Chemical shut its propylene oxide and SM unit after an unexpected equipment failure on Dec. 24. The facility, with the capacity to produce about 200,000 mt/year of PO and 450,000 mt/year of SM, was taken offline. While some traders initially expected a mid-January restart, the timeline has now slipped to early February, further tightening supply.

Margin pressure has forced even more drastic action in Shandong province. Shandong Chambroad Styrenova Innovative Materials Technology shut its entire site — comprising two SM lines of 600,000 mt/year and 70,000 mt/year — from Oct. 13. The plant was initially scheduled to restart in H2 November, but the restart has been delayed until the end of the year as negative margins made operations uneconomic.

Meanwhile, Sinopec Zhenhai Refining & Chemical, or ZRCC, shut its 620,000 mt/year PO/SM plant for turnaround on Sept. 24. The restart, originally slated for H2 November, has now been postponed until the end of 2025. Hengli Petrochemical is also scheduled to shut its 720,000 mt/year SM plant from November through year-end, following an earlier April–May turnaround, with market sources citing weak earnings.

Looking ahead, sentiment in China’s SM market has improved. Traders point to supportive macro expectations, constrained supply under government measures aimed at curbing excessive internal competition, and the prospect of stronger demand. Downstream projects are expected to add about 1.7 million mt/year of new SM consumption capacity. Although around 1.399 million mt/year of new SM capacity is projected to come onstream in 2026, many market participants expect delays due to margin pressure and lingering oversupply concerns.

“The fundamentals look healthier than they did a few months ago,” said the China-based trader. “Supply discipline is improving, exports are doing their job, and demand should gradually recover. It’s not a bull market yet, but the worst feels like it’s behind us.”

—Reporting by Hazel Kumari, hkumari@opisnet.com; Editing by Mei-Hwen Wong, mwong@opisnet.com