WHAT IS IT?
Caustic soda (sodium hydroxide, NaOH) is a white solid or aqueous solution that is one of the most widely used industrial chemicals. It is produced via electrolysis of salt water (chlor-alkali process), simultaneously producing chlorine gas.
FORMS
Liquid Caustic Soda (LCS): 32% or 50% NaOH solution. Easiest to handle, most commonly traded.
Caustic Soda Flakes: 98–99% NaOH solid. Easier to store and ship than liquid but requires dissolving.
Caustic Soda Pearls/Prills: Small beads, 98–99% NaOH. Used in applications requiring easy dosing.
CHLOR-ALKALI LINK
Caustic soda and chlorine are always produced together (1.1 tonnes caustic soda per 1 tonne chlorine). When chlorine markets are strong, caustic soda production increases and prices fall — and vice versa. This inverse relationship is key to understanding price movements.
KEY USES
Alumina production from bauxite (Bayer process) — largest single use
Pulp and paper (kraft process)
Textile manufacturing (mercerisation of cotton)
Soap and detergent manufacturing
Water treatment (pH adjustment)
Chemical manufacturing (various derivatives)
Food processing (curing olives, making pretzels)
TRADE CORRIDORS
Major exporters: China, USA, South Korea, Japan
Major buyers: Southeast Asia, India, Australia (for alumina refining), Latin America
Tetra relevance: South Korea and China → SEA corridor. Indonesia has large alumina industry.
PRICING BASIS
No single global benchmark. Regional spot markets: FOB Korea, CFR Southeast Asia, FOB China.
Prices inversely correlated with chlorine demand — follow the chlor-alkali balance.
SPECIFICATIONS (Liquid 50%)
NaOH: 50.0% ± 0.5%
NaCl: max 0.03%
Na₂CO₃: max 0.1%
Fe: max 5 ppm
Colour: clear to slightly yellow
SAFETY
Highly corrosive — causes severe burns. Reacts violently with acids. IMDG Class 8 (Corrosive). Requires corrosion-resistant ISO tanks or lined drums.