Salt

Salt (sodium chloride) is one of the oldest, cheapest, and most essential commodities in human history, and one of the very few that has never been financialized. World production runs roughly 290 to 300 million tonnes a year, with China and the United States the two largest producers, followed by India, Germany, Canada, Australia, Chile, and Mexico. It sits in the petrochemicals group here for a specific reason: its single largest global use is as a chemical feedstock. (It is, strictly, an industrial mineral rather than a petrochemical.)

The biggest surprise about salt is what it is for. Most people picture the table shaker, but food is a single-digit share of consumption. The largest use worldwide is the chemical industry, specifically chlor-alkali production, where salt is electrolyzed into chlorine and caustic soda (sodium hydroxide), the feedstocks for PVC, solvents, and a vast range of chemicals. The second great use, especially in the US, Canada, and northern Europe, is winter road de-icing, which in a hard winter is the single largest use in the United States. Water treatment and softening take a further slice, and only a small remainder is food and table salt. Salt is made three ways: rock-salt mining from underground beds, solar evaporation of seawater or brine in warm dry climates, and vacuum and brine evaporation for high-purity grades.

Salt has no futures market and never has. It is extraordinarily cheap, on the order of 50 to 130 dollars a tonne depending on grade, and so heavy that freight routinely costs more than the salt itself, which keeps it a regional, localized market rather than a single national or global price. De-icing salt is bought through annual municipal and state procurement tenders ahead of winter; chemical-grade brine is often produced captively on-site by the chlor-alkali plant that consumes it or sold on long-term contract. The result is that one of the commodities most central to chemistry and to keeping winter roads open has no ticker, no exchange, and no speculative market at all.

For most of history salt was anything but cheap. Before refrigeration it was the main way to preserve food, salting and brining meat and fish to last the winter, which made it a strategic necessity worth fighting and taxing over. Saharan caravans hauled slabs of salt south to trade for West African gold near Timbuktu; medieval France ran the hated gabelle salt tax for centuries; and salt is woven into language itself. The word salary comes from the Latin salarium, rooted in sal, salt, though the popular tale that Roman soldiers were literally paid in salt is a myth: they were paid in coin, and salarium most likely meant an allowance to buy salt and provisions. The phrase worth his salt carries the same old sense of the stuff as something valuable. What changed was supply: industrial mining and evaporation through the nineteenth and twentieth centuries turned a precious good into one of the cheapest commodities on earth.

The one exception to salt's cheapness is the gourmet shelf, which is almost entirely marketing. Himalayan pink salt is mined not in the Himalayas but at the Khewra mine in Pakistan, one of the world's oldest and largest, and its pink tint is simply trace iron oxide; chemically it is about 98 percent sodium chloride, like any other salt, and its much-advertised trace minerals are present in nutritionally meaningless amounts. The same is true of the hand-harvested specialty salts, fleur de sel, Maldon flakes, Celtic sel gris, and Hawaiian salt: prized for texture and provenance, but still essentially NaCl. What they share is the markup. Bulk rock salt sells for around 50 dollars a tonne, while fleur de sel can fetch the equivalent of tens of thousands of dollars a tonne, a thousandfold premium for what is chemically the same compound.

And there is no prospect of ever running out. The oceans alone hold on the order of fifty quadrillion tonnes of dissolved salt, enough to bury every continent under a layer more than 150 meters thick, and beneath the land lie vast beds of halite, the rock salt left behind by ancient seas that dried up; the Khewra mine alone holds hundreds of millions of tonnes. Salt is, for practical purposes, inexhaustible, which is the deepest reason it has no futures market: its price reflects the cost of digging it up and shipping it, not any scarcity in the ground, and a commodity that can never be cornered or run short gives a speculator nothing to trade.