NaOH (Caustic Soda – Sodium Hydroxide) Comprehensive Guide: Concentration, Applications & Where to Buy from Reputable Sources in 2026
NaOH (Sodium Hydroxide, lye, caustic soda, CAS 1310-73-2) is a strong alkaline chemical available as a white solid (flakes/granules) or a colorless liquid solution; it dissolves completely in water with a strong exothermic reaction. NaOH is used in nearly all industries: wastewater treatment (pH adjustment, metal precipitation), kraft paper production (pulp cooking), soap and detergents, textile dyeing (fiber sizing, mercerizing), and hundreds of other applications. Loc Thien Chemicals supplies B2B NaOH in various concentrations (20–50%) and solid forms (99% flakes), complete with COA/MSDS per batch—delivered to industrial parks nationwide within 24 hours.
This article is a comprehensive guide to NaOH for process engineers and industrial chemical buyers: properties, comparison of common concentrations, liquid vs. flakes vs. granules, 5 main applications, density chart, safety guidelines, and trusted suppliers.
5 Key Points to Remember:
- NaOH (CAS 1310-73-2) — a strong alkali; dissolves in water with heat release; severely corrosive to skin and eyes. Always use full PPE.
- Common commercial concentrations: 20%, 32%, 45%, 48%, 50% (liquid) and 99% (solid flakes/granules). Select the concentration based on transportation requirements, dilution needs, and total cost of ownership (TCO).
- Liquid caustic soda vs. flake caustic soda: Liquid is convenient for metered pumping; flakes save on long-distance shipping costs — see the detailed comparison table below.
- 5 Key Applications: Wastewater treatment, Kraft paper, soap, textile dyeing, and swimming pools/industrial cleaning — always test dosages on actual systems.
- B2B Purchasing: Get a quote in 15 minutes via hotline 0979 891 929; COA/MSDS provided per batch; delivery to industrial parks nationwide.
What is NaOH? Physical and Chemical Properties
NaOH (Sodium Hydroxide, also known as lye or caustic soda) is a strong base with the formula NaOH, a molar mass of 40.00 g/mol, and CAS number 1310-73-2. Under normal conditions, pure NaOH is a white solid in the form of flakes, granules, or powder; it is highly hygroscopic and dissolves very well in water with an exothermic reaction: NaOH(s) → Na⁺ + OH⁻ + heat. NaOH solutions have a pH >13 at concentrations of 1% or higher—placing it among the most strongly corrosive alkaline chemicals in industry.
In the Vietnamese market, NaOH is supplied in two main forms: liquid (concentrations of 20%, 32%, 45%, 48%, 50%) transported by tanker trucks, IBCs, or drums, and solid form (99% flakes or 99% granules) packed in 25-kg bags. Domestically produced liquid NaOH offers price and logistics advantages for customers in the South; NaOH flakes are typically imported from China, India, and Taiwan.
| Criterion | NaOH (Sodium Hydroxide) |
|---|---|
| CAS Number | 1310-73-2 |
| Formula | NaOH |
| Molar mass | 40.00 g/mol |
| Commercial forms | Liquid 20–50% · Flakes 99% · Granules 99% |
| Density (32%) | ~1.35 g/mL at 20°C |
| pH (1% solution) | >13 |
| Packaging | 200L drums · 1,000-L IBC · Tank truck · 25-kg bags (flakes/granules) |
| Documentation | COA · MSDS/SDS · VAT invoice |
Comparison of Common NaOH Concentrations
Each NaOH concentration has its own advantages and disadvantages regarding price, logistics, and applications. The table below helps buyers select the right concentration based on TCO (Total Cost of Ownership):
| Concentration | Form | Advantages | Disadvantages | Typical Applications |
|---|---|---|---|---|
| NaOH 20% | Liquid | Safer to handle | High shipping costs (contains 80% water) | Swimming pools, light cleaning |
| NaOH 32% | Liquid | Balanced cost/logistics, most common | Solidifies at <15°C | Wastewater treatment, acid neutralization |
| NaOH 45% | Liquid | Saves on shipping costs compared to 32% | Requires heating/insulation in cold weather | Kraft paper, textile dyeing |
| NaOH 48–50% | Liquid | Highest NaOH concentration in liquid form | Requires specialized equipment; solidifies at ~12°C | Large plants, chemical production |
| NaOH 99% | Flakes/Granules | No water content, lowest shipping costs | Requires a mixing tank; releases significant heat upon dissolution | Customers far from the warehouse, long-term storage |
⚠️ Principles for Selecting Concentration: There is no “best” concentration—only the concentration that aligns with the plant’s total cost of ownership (TCO). Contact Lộc Thiên for consultation on selecting the appropriate concentration based on: transportation distance, storage tank infrastructure, consumption capacity, and budget.
Liquid Caustic Soda vs. Flake Caustic Soda vs. Granular Caustic Soda — Which Form Should You Choose?
| Criteria | Liquid Caustic Soda (20–50%) | 99% Flake Caustic Soda | 99% Granular Caustic Soda |
|---|---|---|---|
| NaOH Content | 20–50% | 99% | 99% |
| Shipping Costs | High (water transport) | Low | Low |
| Ready to use | Direct pumping | Must be dissolved | Must be dissolved |
| Heat release during mixing | Negligible | Significant (cooling required) | Significant (cooling required) |
| Storage | Carbon steel or HDPE tanks | 25 kg bags, dry location | 25 kg bags, dry location |
| Suitable scale | Consumption >5 metric tons/month | Low consumption, far from warehouse | Low consumption, far from warehouse |
| Price/kg of pure NaOH | Lower (domestically produced) | Higher (imported) | Higher (imported) |
Recommendation: Plants in Southern Industrial Zones with consumption >10 metric tons/month → choose 32% or 45% liquid caustic soda delivered by tanker truck. Factories in the Central/Northern regions or with consumption <5 metric tons/month → consider 99% flake caustic soda to save on transportation costs.
5 Major Industrial Applications of NaOH
1. Wastewater Treatment — pH Adjustment & Metal Precipitation
NaOH is the number one pH-adjusting chemical in industrial wastewater treatment. NaOH raises the pH of acidic wastewater to neutral while precipitating heavy metals as hydroxides: Fe³⁺ + 3OH⁻ → Fe(OH)₃↓, Cr³⁺ + 3OH⁻ → Cr(OH)₃↓. The NaOH dosage depends on the acidity and composition of the wastewater—always conduct a jar test before scaling up.
2. Kraft Paper Production — Wood Pulp Cooking
NaOH is the primary chemical in the Kraft (sulfate) process: it dissolves lignin in wood chips at 160–170°C under high pressure, releasing cellulose fibers. The NaOH dosage is approximately 6–8% of the dry wood weight. The paper industry is the world’s largest consumer of NaOH.
3. Soap & Detergent Production
NaOH hydrolyzes fats and oils (triglycerides) into glycerol and sodium salts of fatty acids—which is soap. Saponification reaction: Fats + NaOH → Glycerol + Soap. This is the oldest application of NaOH and still accounts for a significant portion of consumption.
4. Textile Dyeing — Mercerizing Cotton Fibers
20–25% NaOH is used in the mercerizing process (to impart luster to cotton fibers): cotton fibers are soaked in cold NaOH, which causes the fibers to swell, increasing their luster, dye uptake, and mechanical strength. After treatment, excess NaOH is recovered and reused to reduce costs and environmental impact.
5. Industrial Cleaning & Swimming Pool Water Treatment
20–32% NaOH is used in CIP (Clean-in-Place) cleaning for food and beverage production lines. In swimming pool water treatment, NaOH raises the pH after chlorine is added (chlorine lowers the pH), maintaining an optimal pH of 7.2–7.6 for effective disinfection and swimmer safety.
Safety Guidelines for Using NaOH
NaOH is an extremely corrosive chemical. Skin contact causes deep alkaline burns that are difficult to heal. Eye contact can cause permanent blindness. Ingestion can cause esophageal perforation and death.
Mandatory PPE: Sealed chemical-resistant goggles · Butyl/neoprene rubber gloves · Chemical-resistant suit · Safety boots · Full-face respirator when mixing solid NaOH.
Emergency First Aid:
- Skin: Rinse under running water for ≥15 minutes; remove contaminated clothing. Do not neutralize with acid.
- Eyes: Rinse eyes under clean running water for ≥15 minutes; seek medical attention immediately.
- Ingestion: DO NOT induce vomiting. Drink clean water (if the victim is conscious). Seek emergency medical attention immediately.
Storage: Carbon steel or HDPE tanks for liquid NaOH. Store NaOH flakes/granules in sealed 25-kg bags in a dry place. Incompatible with: strong acids (violent exothermic reaction), aluminum, zinc, and tin (produces flammable and explosive H₂ gas).
Loc Thien — Nationwide B2B NaOH Supplier
Loc Thien Chemicals supplies industrial-grade NaOH to hundreds of factories in key industrial zones. Our capabilities are verified by concrete evidence:
1. A network of 6 warehouses nationwide: Warehouse 1 — Mỹ Xuân, Bà Rịa - Vũng Tàu; Warehouse 2 — Long Thành, Đồng Nai; Warehouse 3 — Tân Đông Hiệp B Industrial Park, Dĩ An, Bình Dương; Warehouse 4 — Hòa Khánh Industrial Park, Đà Nẵng; Warehouse 5 — Ô Môn Industrial Park, Can Tho; Warehouse 6 — Dai Dong - Hoan Son Industrial Park, Bac Ninh. 24-hour delivery to all industrial parks.
2. A fleet of 20 specialized tanker trucks: Transporting liquid NaOH directly to customers’ storage tanks. Tank trucks undergo regular maintenance and meet safety standards for transporting alkaline chemicals.
3. COA/MSDS for each batch: Each batch shipped includes a COA (actual concentration, specific gravity, impurities) and an MSDS/SDS. Verify the COA upon receipt.
4. Technical Consultation: Assistance in selecting the optimal NaOH concentration/form, advice on switching from flake caustic soda to liquid caustic soda, TCO calculations, and recommendations for dilution equipment.
Frequently Asked Questions About NaOH
Is NaOH toxic? How is it different from acid?
NaOH is not “toxic” in the sense of being a chemical poison, but it is extremely corrosive. Alkali burns are typically more severe than acid burns because alkalis penetrate deeply into tissue, react with skin lipids (saponification), and are difficult to rinse off completely. Always use full PPE when handling NaOH at any concentration.
32% and 45% NaOH — Which One Should You Choose?
32% NaOH is the most common concentration and is suitable for most wastewater treatment systems and medium-sized plants. NaOH 45% saves ~30% on shipping costs (calculated per kg of pure NaOH) but requires equipment capable of handling higher concentrations and may solidify at low temperatures. The decision should be based on total cost of ownership (TCO), not just the unit price.
Liquid Caustic Soda vs. Caustic Soda Flakes — Which Is Cheaper?
99% caustic soda flakes have a higher unit price per kg of pure NaOH (imported), but shipping costs are significantly lower (no water is transported). Domestically produced liquid caustic soda has a lower unit price but higher shipping costs. “Cheaper” depends on the overall TCO: if the plant is close to the warehouse → liquid caustic soda; if the plant is far from the warehouse → caustic soda flakes.
Where to Buy NaOH at a Good Price with Consistent Quality?
Purchase from a supplier that provides COA/MSDS per batch, has clearly identified warehouses, and has the capacity to deliver to industrial parks. Loc Thien Chemicals — 6 warehouses nationwide, 20 dedicated tanker trucks — supplying 20–50% liquid NaOH and 99% flake NaOH with COA/MSDS; get a B2B quote within 15 minutes via hotline 0979 891 929.
Can NaOH be used in food?
NaOH is used in food processing (E524) at very low concentrations and must meet food-grade standards. Loc Thien’s industrial-grade NaOH is intended for industrial applications and is NOT for food use.
Get a NaOH Quote in 15 Minutes
Need NaOH for wastewater treatment, paper production, soap making, or textile dyeing? Get a fast, accurate quote with all necessary documentation.
Hotline: 0979 891 929 | Website: hoachatlocthien.com
Please have the following ready: desired concentration · form (liquid/flakes/granules) · estimated quantity · delivery location.
Our Commitment: Quote within 15 minutes · COA/MSDS per batch · on-time delivery · lifetime technical support for your order.
LOC THIEN INVESTMENT AND DEVELOPMENT CO., LTD.
- Address: 452/6B Provincial Road 10, Binh Tri Dong Ward, Binh Tan District, Ho Chi Minh City
- Phone: 028 6269 5669 - 028 6269 5662
- Hotline: 0979 891 929
- Website: hoachatlocthien.com