Global Sulfur Supply Disruption Due to Strait of Hormuz Blockade (Updated April 2026)

Updated April 1, 2026

The escalation of the military conflict between the United States, Israel, and Iran on February 28, 2026, has triggered a severe and ongoing disruption to global sulfur supply chains. Following coordinated airstrikes by the US and Israel on Iranian territory under Operation Epic Fury, which resulted in the death of Iran's Supreme Leader Ali Khamenei, the Islamic Revolutionary Guard Corps (IRGC) declared the Strait of Hormuz closed on March 4 and issued threats against any vessel attempting to transit the waterway. As of April 1, the crisis has entered its fifth week with no resolution in sight.

The Strait of Hormuz is the most critical maritime chokepoint for global sulfur trade, handling approximately 44% to 50% of worldwide seaborne sulfur shipments. Major sulfur export terminals located in the Persian Gulf, including Jubail in Saudi Arabia, Ruwais in the United Arab Emirates, and Imam Khomeini Port in Iran, all depend on the Strait for access to the Indian Ocean and global markets. Commercial transit through the Strait collapsed by approximately 90% during the first week of March and has remained near zero for most non-approved vessels since then. Iran, Kuwait, Qatar, Saudi Arabia, and the UAE combined to produce nearly a quarter of the world's sulfur supply in 2025.

The disruption was compounded by direct physical damage to production facilities in the region. Iranian retaliatory strikes hit Qatar's Ras Laffan Industrial City and Mesaieed Industrial City, prompting QatarEnergy to halt production of LNG, sulfur, urea, methanol, polymers, and aluminum. Ras Laffan alone supplied approximately 10,000 tonnes per day of liquid sulfur for export. Saudi Aramco's Ras Tanura refinery, with a capacity of 102,000 tonnes per year of sulfur, was also shut down after being struck by debris from intercepted Iranian drones. Iran itself banned all food and agricultural product exports to protect domestic supply, further tightening global availability. More than 3 million barrels per day of regional refining capacity has been shut down due to strikes and loss of viable export outlets, further reducing sulfur byproduct output.

The sulfur market was already under significant stress before the conflict. Global sulfur prices had surged more than 100% throughout 2025, driven by constrained supply from Russian refinery damage, rising demand from Chinese lithium iron phosphate battery production, and expanding nickel processing operations in Indonesia. The global sulfur supply gap was estimated at approximately 5.13 million tonnes heading into 2026. US sulfur prices had increased 165% year-over-year to over $650 per metric ton before the war, and have surged an additional 25% since the conflict began. The sulphuric acid market had already seen a 500% price increase before the latest Middle East disruption. The International Energy Agency has described the crisis as the largest disruption to the energy supply in history, exceeding any single previous event.

China, the world's largest sulfur importer, is particularly exposed. The country imported 9.61 million tonnes of sulfur in 2025, with nearly 40% originating from the UAE, Saudi Arabia, Kuwait, Oman, and Iran, and an overall import dependency approaching 50%. As of late February 2026, Chinese port inventories stood at approximately 1.8 million tonnes, sufficient for only 1.2 to 1.5 months of consumption during the critical spring planting season. Domestic sulfur prices in China jumped to 4,250 yuan per tonne immediately after the conflict began. The situation has worsened as the blockade persists into its fifth week, with sulfur prices in Northeast Asia reaching approximately $610 per kilogram in March 2026, a 5.1% monthly increase. Asian traders have been scrambling to find alternative supplies, but availability from other regions such as Canada remains limited.

On March 26, Iran's Foreign Minister Abbas Araghchi announced that ships owned by five nations, including China, Russia, India, Iraq, and Pakistan, would be allowed to transit the Strait. Malaysia and Thailand were later granted access through diplomatic talks. Iran also agreed on March 27 to a United Nations request to allow humanitarian and fertilizer shipments through the strait, an acknowledgment of the growing global food security threat. Two large Chinese-owned containerships, the CSCL Arctic Ocean and CSCL Indian Ocean, were allowed to transit on March 30 after initially being turned back. However, these limited passage agreements have not meaningfully restored bulk sulfur trade flows, and some ships from approved nations have still been blocked or turned back. Iran's parliament has advanced legislation to impose tolls on vessels transiting the Strait, with ships reportedly paying up to $2 million per crossing.

The disruption has severe downstream consequences for the Central African Copperbelt, particularly in the Democratic Republic of the Congo and Zambia. The Copperbelt imports approximately 2 million tonnes of sulfur annually, primarily from the Middle East. This sulfur is converted into roughly 6 million tonnes of sulphuric acid through local sulfur burners, which is essential for leaching copper from oxide ores. More than 90% of sulfur imported into Africa originates from the Middle East and must transit the Strait of Hormuz. Africa has virtually no domestic sulfur production to serve as a buffer against the shock.

The DRC is the world's second-largest copper producer, with output reaching 3.2 million tonnes in 2025, and also accounts for roughly 70% of global mined cobalt supply, which also requires sulphuric acid for processing. Copper oxide ore is the dominant source in the DRC, and sulphuric acid is the primary reagent used to extract the metal through heap leaching. Prior to the Hormuz crisis, high-strength sulphuric acid prices in Kolwezi, on the western edge of the DRC Copperbelt, were already trading near all-time highs of $700 to $800 per tonne due to regional export restrictions, elevated copper prices, and an already tight global sulfur market. Zambia had imposed an export ban on sulphuric acid in September 2025, further constraining regional supply.

Robert Friedland, founder and Executive Co-Chairman of Ivanhoe Mines, warned in early March that traders were already struggling to source any sulphuric acid, and that if the disruption lasted beyond approximately three weeks, copper oxide operations in the DRC would have to close as acid stockpiles were depleted. With the blockade now exceeding four weeks, African mining operators have been forced to implement mitigation strategies including the processing of higher-grade ores to maximize metal output per tonne of acid consumed. Bloomberg Intelligence estimates that 50% to 60% of DRC copper output depends on sulphuric acid, and sulphur shortages could cap the country's mine supply growth, limiting any surplus to 100,000 to 200,000 tonnes. The crisis has been compounded by the collapse of the Kasumbalesa Bridge on March 3 due to heavy flooding, cutting off one-third of the DRC's outbound refined copper shipments and stranding thousands of trucks.

Ivanhoe Mines' Kamoa-Kakula copper complex has been ramping up its on-site smelter near Kolwezi, which is expected to produce up to 700,000 tonnes per year of high-strength sulphuric acid at full capacity. By early March 2026, the smelter had reached approximately 60% of capacity, producing around 1,200 tonnes per day of 98%-pure acid. This local production capacity is of critical strategic importance to the DRC mining sector during the current crisis. Bloomberg Intelligence has noted that the ramp-up of this smelter provides a domestic source of sulphuric acid that eases dependence on Gulf supply.

Beyond copper mining, the sulfur supply disruption threatens global agriculture. Sulfur is a primary feedstock for sulphuric acid, which is essential for phosphate fertilizer production. The Middle East accounts for approximately 40% to 50% of traded nitrogen fertilizer volume. The disruption affects 44% of global sulfur trade, 31% of urea trade, 18% of ammonia trade, and 15% of phosphate trade. Urea prices have increased by approximately 50% since the start of the war as of late March 2026. The timing is particularly damaging as Northern Hemisphere farmers prepare for spring planting season, and unlike oil, the fertilizer sector does not have internationally coordinated strategic reserves to cushion the blow. The UN World Food Program estimates that if oil prices remain above $100 per barrel into mid-2026, the number of people experiencing food insecurity could rise by 45 million to a record 363 million globally.

The crisis extends to sulfuric acid supply for the global semiconductor industry. Ultra-high-purity sulfuric acid is essential for cleaning and etching silicon wafers used in advanced microchip manufacturing. Taiwan, which produces nearly 90% of the world's most advanced semiconductors through TSMC, sources roughly 30% of its LNG from Qatar through the Strait of Hormuz. Taiwan's gas reserves are estimated at roughly 10 to 11 days under normal consumption levels, raising the prospect of electricity shortages affecting the island's technology sector.

War-risk insurance cancellations have effectively enforced the blockade beyond physical military threats. Major container shipping companies including Maersk, CMA CGM, MSC, and Hapag-Lloyd have suspended regional operations. Over 150 tankers were initially stranded outside the Strait, unable to deliver their cargo, and estimates suggest approximately 2,000 vessels are now stranded on either side of the waterway. The crisis represents the first time in modern history that LNG tanker movement through the Strait has dropped to zero. Iran has made at least 21 confirmed attacks on merchant vessels since the blockade began, killing at least seven seafarers.

On March 11, the International Energy Agency coordinated the largest emergency oil reserve release in its history, with all 32 member countries unanimously agreeing to release 400 million barrels, more than twice the previous record set in 2022. The US Department of Energy released 172 million barrels from its Strategic Petroleum Reserve. However, IEA Executive Director Fatih Birol warned on April 1 that the situation would worsen significantly in April, as the last pre-war cargoes that were already in transit have now been delivered. According to Birol, the loss of oil in April will be twice that of March, and the current crisis surpasses any previous energy disruption in history. Brent crude surged more than 60% during March, the largest monthly price gain since records began in the 1980s, peaking at $126 per barrel.

The situation remains highly volatile. On April 1, President Trump claimed that Iran's president had requested a ceasefire, stating the US would consider the request only when the Strait of Hormuz is "open, free, and clear." Iran's Foreign Ministry dismissed the claim as "false and baseless," while the IRGC stated the strait remained "fully" under its control. Trump had previously paused strikes on Iran's power grid until April 6, citing progress in negotiations. Iran has received Trump's 15-point peace plan and responded with a five-point counteroffer that would give Tehran control over the Strait. Trump is expected to deliver a primetime address to the nation on the evening of April 1. If the blockade continues, sulphuric acid prices will exceed previous records, copper oxide mining operations across the DRC will face sustained production suspensions, fertilizer costs will escalate further worldwide, and the resulting food price increases will fall hardest on developing nations in Africa and South Asia.