The Fertilizer Institute, via Fertilizer Daily's 18 August write-up of president Corey Rosenbusch's 6 August interview, framed sulfur as the next phosphate bottleneck. The item is at https://www.fertilizerdaily.com/20260818-sulfur-shortage-phosphate-supply-afi-hormuz-warning/. More than half of globally traded sulfur normally transits Hormuz, and commercial shipments have been described as near-zero since the Iran conflict.
Russia extended its sulfur export ban through end-2026, taking two of the three largest traded sources offline together. Rosenbusch said the squeeze already cut output at multiple US phosphate plants, including four Mosaic units earlier in the summer. He asked Washington to treat sulfur as a supply-chain bottleneck alongside nitrogen and potash.
Mosaic settled Q3 molten sulfur at $705 per long ton, the last public Tampa contract figure named in that interview. Argus open news on 13 July had already put the Tampa Q3 delivered molten contract at that same $705 per long ton, up $50 from $655 in Q2, after Q2 had cleared the 2008 peak. The Argus item is at https://www.argusmedia.com/en/news-and-insights/latest-market-news/2851577-tampa-3q-liquid-sulphur-price-hits-record-705-lt.
Sulfuric acid on phosphate rock is why Tampa molten sulfur exists as a contract. When sulfur tonnes do not arrive, MAP and DAP plants do not run a full rate. CRU reported OCP cut Moroccan phosphate capacity by up to 50 percent through Q2 2026. Mosaic also curtailed at three US and Brazil locations in that CRU account. TFI's August interview is the US trade-association version of the same rationing.
Alberta tonnes on the Vancouver stem and US Gulf solids are the two North American answers while Middle East seaborne stays shut. USGS MCS 2026 put Canada at 53 percent of US recovered elemental sulfur imports for 2021-24. SMM put 2025 Canadian sulfur exports at 4.25 million tonnes and first-four-month 2026 on a 5.22 million tonne annualized pace, with Alberta and British Columbia more than 95 percent of the national account.
TFI's March 2026 conflict brief had already put high-risk Gulf exporters (Saudi Arabia, Bahrain, UAE, Kuwait, Qatar) at about 41 percent of global sulfur exports in 2025, with Iran adding about 4 percent, and nearly 50 percent of global sulfur trade tied to Hormuz exposure. US import reliance on conflict-exposed supply was estimated at 10-20 percent of domestic supply. The August interview is that brief after a summer of plant cuts.
Phosphate affordability is the demand-side limit on how far Tampa can chase Gulf spot solids. Argus in the 13 July item described US Gulf spot exports at $1,100-1,150 per tonne FOB, well above the $705 per long ton molten contract. Some Gulf producers lack solid-export infrastructure and remain tied to domestic molten consumers. If Florida runs stay curtailed, those tonnes have nowhere cheap to go.
Itafos Conda's May switch from the Vancouver sulfur index to Tampa, reported 9 August, shows a Western US acid plant choosing the Florida contract after both hubs rerated. CEO David Delaney said Tampa sat below Vancouver through the second quarter. TFI's bottleneck language is therefore a two-hub North American problem, not only a Tampa problem.
Rosenbusch's named request to Washington is policy, not a tonne. The tonnes sit in Alberta block, Vancouver loaders, and US Gulf forming. Until Hormuz dry bulk and Russian exports return, those three North American stocks are the phosphate system's working inventory.
Quotes in this item are Rosenbusch as reported by Fertilizer Daily. No unnamed analysts are invented. Licensed weekly assessment grids are not restated.