Product Overview
Sodium Hydroxide 50% Solution ACS Grade — also known as caustic soda — is a concentrated alkaline liquid supplied at 50% by weight in aqueous solution. This is the form most water treatment operators, chemical manufacturers, and QC labs order when they need a strong base that pours and meters without the exothermic dissolution step that pellets or flakes demand. CAS Number: 1310-73-2.
Available to order from 1-quart bottles for bench-scale work through 330-gallon totes for continuous-feed industrial processes.
Why This Concentration
At 50%, this solution delivers the highest practical concentration of sodium hydroxide that remains pumpable and handleable as a liquid at normal ambient temperatures. Below roughly 30%, you are paying freight on water. Above 50%, the solution's freezing point climbs and crystallization becomes a real storage problem in cooler facilities. For pH control in water treatment plants or CIP cleaning loops, 50% is the standard working concentration — it minimizes dilution math and feeds directly into metering pumps or eductor systems.
The ACS Grade designation tells the buyer this product was procured to a tighter specification window than technical or industrial grades. Labs running titrations, standardizing reagents, or preparing analytical solutions typically specify ACS Grade to reduce the variable of feedstock inconsistency between lots. For process work where the specification tolerance is wider — neutralization, soap manufacturing, general cleaning — a technical grade at the same concentration may be more cost-effective. Match the grade to the precision your process actually requires.
Chemical Profile
Sodium hydroxide solution is a colorless, odorless liquid — noticeably denser than water at 1.53 g/mL (50% w/w aqueous solution, 20 °C). The molecular formula is NaOH with a molecular weight of 39.997. Sodium hydroxide is highly soluble in water. Vapor pressure is approximately 0 mmHg at ambient conditions, meaning the solution does not produce significant vapors at rest — though misting during agitation, pumping, or open transfer still demands respiratory protection. Contact with this solution will severely irritate skin, eyes, and mucous membranes. It is corrosive to metals and tissue.
Industrial Applications
Sodium hydroxide 50% solution is one of the most widely consumed industrial chemicals. Its role varies by industry, but the core function is the same: delivering hydroxide ions in a controlled, metereable form.
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pH Adjustment and Water Treatment — Municipal and industrial water treatment facilities use sodium hydroxide to raise the pH of acidic influent, neutralize process streams, and condition water before discharge. The 50% concentration allows operators to make precise pH adjustments through standard chemical feed equipment without excessive dilution volume.
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Chemical Manufacturing — Sodium hydroxide serves as a primary reactant in the production of numerous downstream chemicals, including sodium salts, detergents, and organic intermediates. Manufacturers rely on the liquid form for direct reactor charging and continuous-process dosing.
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Soap and Detergent Production — In saponification, sodium hydroxide reacts with fats and oils to produce soap. The 50% solution simplifies handling and proportioning compared to dissolving solid caustic on-site, reducing both cycle time and operator exposure risk.
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Laboratory Reagent — Analytical labs use ACS Grade sodium hydroxide solution for titrations, pH buffer preparation, and sample digestion. The liquid form eliminates the dissolution step and the heat management it requires, which matters when preparing standardized solutions where temperature control affects accuracy.
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Industrial Cleaning — Caustic solutions break down grease, oils, proteins, and other organic residues in CIP systems, parts washers, and tank cleaning operations. At 50%, the product can be diluted to the target cleaning concentration on-site, giving maintenance teams a single bulk feedstock for multiple cleaning protocols.
Handling & Storage
Signal word: Danger (per the product's GHS classification).
- H290: May be corrosive to metals (per the product's GHS classification).
- H314: Causes severe skin burns and eye damage (per the product's GHS classification).
Store in HDPE, polypropylene, or other alkali-compatible containers in a cool, dry, well-ventilated area. Keep away from acids — mixing sodium hydroxide with any acid generates intense exothermic heat and can cause violent spattering. Avoid contact with aluminum, zinc, tin, and other amphoteric metals, which corrode on contact and generate flammable hydrogen gas.
Minimum PPE during transfer and handling: chemical-splash goggles, face shield, chemical-resistant gloves (neoprene or butyl rubber), and a chemical-resistant apron. For any operation that generates mist or aerosol — pumping, pressure transfer, open pouring — add NIOSH-approved respiratory protection. Ensure an emergency eyewash and safety shower are accessible within the immediate work area.
Hazmat & Shipping
This product is regulated for transport as a hazardous material. Every shipment from our Taylor, TX facility is prepared by DOT-trained personnel with proper placarding, packaging, and shipping documentation.
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UN Number: UN1824 (per 49 CFR 172.101)
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Hazard Class: 8 — Corrosive (per 49 CFR 172.101)
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Packing Group: II (per 49 CFR 172.101)
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Proper Shipping Name: SODIUM HYDROXIDE SOLUTION (per 49 CFR 172.101)
Documentation
A Safety Data Sheet (SDS) ships with every order and is available in English, Spanish, French, and Japanese. A lot-specific Certificate of Analysis (COA) is available on request for customers who need to verify incoming material against their quality specifications. A Technical Data Sheet (TDS) with detailed product specifications is also available.
Why Buy from Alliance Chemical
This product is available to order in quantities from a single quart to 330-gallon totes, with SDS documentation in four languages and a lot-specific COA on request — the documentation a QC department actually needs at receiving. Alliance Chemical has served over 55,000 customers since 1998 from our Taylor, TX warehouse, shipping hazmat freight daily under USDOT registration #2188383. Shipping and handling guidance on this page is reviewed by Andre Taki, DOT Hazmat Specialist.
Related Reading
Westlake's Cologne PVC closure and Century Lithium's planned Nevada or Utah chlor-alkali plant, read through the cell arithmetic: 1.128 t of caustic soda per tonne of chlorine, and over 90% of US hydrochloric acid made as a byproduct. Membrane versus diaphragm caustic on a certificate (0.01% vs 1.10% salt), and how to compare strengths by the kilogram. Chlorine, Caustic Soda and Hydrochloric Acid Come Out of One Cell.
