Caustic soda: Feedstocks
Why electricity, not salt, sets the cost
What this tab covers What it is made from and what it feeds: the raw materials and energy per tonne with their share of cost (linked to the commodity table), who is low-cost and why, and the chemicals made from it.Caustic soda shares chlorine's inputs: salt and electricity, plus steam to evaporate. Its supply is set by chlorine demand, not by its own price. Feedstock cost is shared across the ECU, so a producer's competitiveness depends on power price and on how well it can place its chlorine.
Inputs per tonne
| Input | Quantity per tonne | Role | Share of cost | Source |
|---|---|---|---|---|
| NaCl Salt | about 1.5 t per t NaOH | sodium source | about 10% (indicative) | EU BREF 2014 (indicative) |
| Electricity | about 2.2-2.5 MWh per t NaOH (share of ECU) | electrolysis | about 50-60% (indicative) | EU BREF 2014 (indicative) |
| Gas Natural gas | 0.5-1 t steam per t (indicative) | evaporation to 50% and flaking | about 10% (indicative) | indicative |
| Sda Soda ash | about 1.3 t per t NaOH | sodium source | dominant in that route | USGS MCS 2026 (stoichiometric) |
Who is low-cost, and why
US Gulf (cheap gas power), China (coal power) and the Middle East are lowest cost; NE Asia ex-China ran about $58 per ECU above China in Nov 2025, and NW Europe about $560 per ECU cash cost. Europe was the clear high-cost producer in 2022 at up to $1,640 per ECU.
Raw materials on the commodity table
NaCl SaltWhat it is made into
| Product | Note |
|---|---|
| Cl2 Chlorine | co-product |
| Srf Surfactants | neutralises LAB sulphonic acid and saponifies fats |
| VSF Viscose fibre | steeping of pulp in caustic |
| Ssi Sodium silicate | alternative to soda ash route |
| PO Propylene oxide | chlorohydrin route consumes caustic or lime |
| EPX Epoxy resins | dehydrochlorination step |
| CAM Battery cathode materials | co-precipitation of NMC precursors |
| Phe Phenol and acetone | minor uses |