Iodine: Stocks
Why geology is not iodine's constraint
Why geology is not iodine's constraint What this tab covers How much is left and how much is held. For minerals and energy: reserves, current output, years of supply and recycling for the top five countries. For farm commodities: production, ending stocks and stocks-to-use for the top five producers (USDA, October 2026). It also covers inventories and stockpiles.Top five countries: reserves, output and years of supply
| Country | Reserves t iodine | Current output t iodine (2025e) | Years of supply | Recycling |
|---|---|---|---|---|
| Chile | 750,000 | 23,000 | 33 | n/a |
| Japan | 4,900,000 | 9,000 | 544 | n/a |
| Turkmenistan | 70,000 | 800 | 88 | n/a |
| Iran | 40,000 | 700 | 57 | n/a |
| Azerbaijan | 170,000 | 210 | 810 | n/a |
Recycling
US output is withheld (reserves 250,000 t). World reserves exceed 6.3 million t against 34,000 t output (excluding US), so geology is not a constraint (USGS 2026). Small amounts are recycled in the US (USGS); Roskill estimated secondary supply at about 5,000 t in 2012, about 3,000 t of it in Japan. China and Uzbekistan produce but do not report.
Reported reserves exceed 6.3 million t, dominated by Japan at 4.9 million t and Chile at 750,000 t. Against 2025 output, that is roughly 185 years of supply, so geology is not the constraint. Beyond reserves lie seawater and Laminaria seaweeds, which concentrate iodine up to 0.45% of dry weight. Only small amounts are recycled, because most iodine is dispersed in medical, nutritional and feed uses. The United States holds no government stockpile, and there is no exchange inventory to watch.
Reserves
World reserves 6,300,000 metric tons (world total reported as more than 6.3 million) Reserve life 185 years at 2025 production Japan 78% Chile 12% United States 4% Azerbaijan 3% Russia 2% Largest reserve holders, share of world reserves (USGS MCS 2026). Reserves are what is economic to extract today, not what exists.Small amounts of iodine were recycled.