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What Is Sodium Hydroxide? Uses, Grades, and How to Buy Caustic Soda or Lye in Bulk

What Is Sodium Hydroxide? Uses, Grades, and How to Buy Caustic Soda or Lye in Bulk

Jun 12th 2026

What Is Sodium Hydroxide? Uses, Grades, and How to Buy Caustic Soda or Lye in Bulk

Sodium hydroxide goes by many names — caustic soda in a water treatment plant, lye in a soap maker's kitchen, NaOH on a lab shelf, white caustic on an industrial supply invoice. Same compound every time, and one of the most broadly useful industrial chemicals in existence. This guide covers what it is, how it's used, how to choose the right form and grade, and how to buy it in bulk.

What Is Sodium Hydroxide?

Sodium hydroxide (NaOH) is a strong inorganic base, highly soluble in water, that produces a strongly alkaline solution. Solid form: white odorless beads or flakes. Liquid form: clear, colorless solution.

  • CAS Number: 1310-73-2
  • Molecular formula: NaOH
  • pH (1% solution): ~13
  • Melting point: 318°C / 604°F
  • Solubility: Very high — dissolves readily and exothermically in water

It is one of the top 10 most produced chemicals in the U.S., manufactured primarily via the chloralkali process — electrolysis of brine to produce chlorine, hydrogen, and sodium hydroxide simultaneously.

Common Names

  • Caustic soda — standard industrial and water treatment term
  • Lye — traditional term in soap making and food processing (NaOH = bar soap lye; KOH = liquid soap lye)
  • NaOH — chemical formula used in lab and manufacturing
  • White caustic / Soda lye / Sodium hydrate — older trade names

Don't Confuse These Related Compounds

Chemical Formula Common Name pH Key Use
Sodium hydroxide NaOH Caustic soda / lye ~13 Bar soap, water treatment, cleaning
Potassium hydroxide KOH Caustic potash ~13 Liquid soap, biodiesel
Sodium carbonate Na₂CO₃ Soda ash ~11.6 Pool pH, detergents
Sodium bicarbonate NaHCO₃ Baking soda ~8.3 Pool alkalinity, baking

Key distinction: Bar soap requires NaOH. Liquid soap requires KOH. The wrong one produces an unusable product.

Solid Beads vs. Liquid Solution — Which Should You Buy?

Solid beads are preferred when you need precise concentration control, are making soap, processing food, or doing batch work. More NaOH per pound shipped — economical for most buyers. Always add solid NaOH to water (never the reverse) — dissolution generates significant heat.

Liquid (25% or 50% solution) is preferred for continuous dosing systems, metering pumps, CIP systems, and water treatment facilities where a pre-dissolved ready-to-dose product eliminates the dissolution step and heat hazard. Trade-off: you're shipping water weight alongside active ingredient.

Grades: Technical vs. Food Grade (FCC)

Technical grade — appropriate for water treatment, industrial cleaning, chemical synthesis, biodiesel, pulp and paper, and pool pH adjustment.

Food grade (FCC) — required for food processing (pretzels, olive curing, hominy, ramen), soap for food-contact surfaces, brewing and distilling, and any application requiring FCC documentation. Both grades are typically 99%+ purity — the difference is certification and traceability.

Applications by Industry

Water Treatment — Raises pH in drinking water to prevent pipe corrosion; neutralizes acidic wastewater. One of the largest U.S. industrial uses.

Soap Making — The essential ingredient in bar soap via saponification. Cold process and hot process both require NaOH measured precisely to the oil blend's saponification value.

Food Processing — Used in pretzel lye baths, olive curing, hominy/masa (nixtamalization), and ramen noodle production. Food-grade FCC required.

Industrial Cleaning — Breaks down fats, oils, and proteins through saponification. Active ingredient in oven cleaners, heavy-duty degreasers, drain openers, and CIP cleaning compounds.

Biodiesel Production — Catalyst in transesterification of vegetable oils or animal fats into biodiesel and glycerin.

Pulp and Paper — Key chemical in kraft pulping to separate cellulose from lignin; used in bleaching and recycled fiber de-inking.

Chemical Manufacturing — Building block for sodium hypochlorite (bleach), sodium carbonate, sodium phosphates, and hundreds of other compounds.

Textile Processing — Used in cotton mercerization to increase luster, dye uptake, and tensile strength.

Safety and Handling

Sodium hydroxide causes severe burns to skin and eyes — the reaction is not always immediately painful, making it especially hazardous. Always wear chemical splash goggles and chemical-resistant gloves. Add solid NaOH slowly to cold water, never the reverse. Work in ventilated areas. Store sealed and dry — NaOH absorbs moisture and CO₂ from air. Keep away from acids, aluminum, zinc, and brass.

SDS available for all products. We carry chemical-resistant gloves, goggles, and face shields if you need PPE alongside your order.

How to Buy Sodium Hydroxide in Bulk

Level 7 Chemical stocks sodium hydroxide in beads and liquid solution with no minimum order requirements — from a single 50 lb bag to truckload quantities.

→ Browse our full sodium hydroxide category

Net 30 / Net 60 terms available through our Resolve Pay program. Ships from Conway, Arkansas — most U.S. deliveries in 1–4 business days.

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