Sulfur supply crisis deepens as China curbs acid exports

Saturday 18 April 2026 - 13:15

By: Dakir Madiha

Sulfur supply crisis deepens as China curbs acid exports

The war between the United States and Iran has triggered a widening disruption in global chemical supply chains, with sulfur emerging as a critical bottleneck across multiple industries. As the conflict enters its seventh week, repeated closures of the Strait of Hormuz have restricted access to one of the world’s most important transit routes for sulfur, a key industrial input that underpins fertilizer production, metal refining, and semiconductor manufacturing.

Roughly 45 percent of global seaborne sulfur trade moves through the Strait of Hormuz. Iranian forces effectively halted traffic after military operations escalated at the end of February, tightening supply flows at a time of already elevated demand. Sulfur, a byproduct of oil and gas refining, is essential for producing sulfuric acid, one of the most widely used industrial chemicals. Disruptions at this stage of the supply chain are now cascading across agriculture, mining, and manufacturing sectors.

Global sulfur prices have surged sharply since the start of the conflict. In the United States, prices rose by 34 percent in early April alone, while international benchmarks have nearly doubled. Market participants remain cautious despite temporary ceasefire announcements, as short-term truces have failed to restore stable shipping flows. Even when navigation resumes, limited vessel movement continues to constrain supply availability.

The situation worsened after China announced it would impose broad restrictions on sulfuric acid exports starting May 1. As the world’s leading exporter of acid derived from smelting operations, China’s move removes a major source of supply at a moment of intensifying shortages. The decision compounds existing disruptions linked to Gulf instability and further tightens global chemical markets.

The downstream impact is most acute in agriculture. Sulfuric acid is indispensable for producing phosphate fertilizers such as monoammonium phosphate and diammonium phosphate, which are central to global crop yields. Reduced sulfur availability threatens fertilizer output and risks creating supply gaps in key agricultural regions. Producers and distributors in both North America and Europe have already suspended price quotations due to extreme volatility and uncertainty over deliveries.

Morocco’s OCP Group, the world’s largest phosphate exporter, faces potential production slowdowns if it cannot secure its annual sulfur imports from the Gulf, estimated at 3.7 million tonnes. Analysts warn that existing food stockpiles entering 2026 may offer only limited protection against supply disruptions. Projections indicate global food prices could rise by 12 to 18 percent compared with pre-crisis levels by the end of the year.

Efforts to stabilize maritime flows remain fragile. Iran briefly declared the Strait of Hormuz open during a short ceasefire linked to regional tensions, but quickly reversed course after the United States maintained its naval blockade on Iranian ports. The uncertainty surrounding access to the corridor continues to disrupt planning for global trade.

Supply constraints are expected to persist beyond the immediate conflict. Russia has extended its own sulfur export ban through June 2026, further limiting available volumes on international markets. Industry analysts increasingly view the situation not as a temporary energy disruption but as a structural chemical supply shock that is moving upstream through the global industrial system, with long-term implications for prices and production.