Sodium Hydroxide 50% Membrane Grade (Caustic Soda, Lye)

Product Overview

Sodium Hydroxide 50% Membrane Grade — also called caustic soda or lye — is a concentrated aqueous solution of NaOH, one of the workhorse alkalis of American industry. At 50% strength it is the standard commercial concentration for water-treatment plants, chemical processors, soap makers, and textile operations that need strong base on demand without handling dry beads or flake. we distribute it in our Taylor, TX warehouse and ship it daily in DOT-compliant corrosion-resistant packaging, from single quarts for bench work up to 330-gallon totes for production lines.

This is a serious corrosive. The signal word is Danger (per the product's GHS classification), and every order leaves our dock packed, labeled, and documented accordingly.

Why This Concentration

Fifty percent is the concentration most caustic soda is traded at, and for good reason: it delivers the maximum practical alkali per gallon while remaining pumpable at ambient temperature. Buying at 50% means fewer drums per unit of NaOH, lower freight per pound of active base, and no dust exposure or dissolution exotherm that comes with dissolving solid caustic on site. Dilution to a working strength is straightforward — always add caustic to water, slowly, with cooling, because the heat of dilution is significant.

The trade-off is handling. A 50% solution is dense, viscous, and aggressively corrosive to skin and to many metals, and concentrated caustic solutions can begin to crystallize in cold storage, so keep it in a temperate space and off unheated loading docks in winter. If your process only ever needs dilute caustic and you would rather not manage the dilution step, a lower-strength solution may suit you better; if you consume alkali in volume, 50% is the economical choice.

The membrane designation refers to caustic produced by the membrane cell chlor-alkali process, the route buyers specify when they want cleaner caustic than older diaphragm-cell material. Review the technical data sheet and lot documentation to confirm the assay and impurity profile fit your process before committing a batch.

Chemical Profile

Sodium hydroxide solution at 50% is a colorless, odorless liquid, noticeably denser than water — density 1.53 for the 50% w/w aqueous solution at 20 °C. It is fully miscible with water in all practical proportions, and as an aqueous solution it exerts essentially no vapor pressure (approximately 0 mmHg), so the hazard is contact, not inhalation of vapor under normal conditions. Contact severely irritates and burns skin, eyes, and mucous membranes; it is toxic by ingestion and corrosive to metals and tissue. The active compound is sodium hydroxide, formula NaOH, molecular weight 39.997, CAS 1310-73-2.

Industrial Applications

Caustic soda at 50% earns its keep across more industries than almost any other commodity chemical we ship:

• Water treatment — pH adjustment. Operators meter caustic into raw, process, and waste streams to raise pH, neutralize acidity, and condition water ahead of downstream treatment steps. The 50% solution feeds directly into metering pumps or dilution loops.
• Chemical manufacturing — synthesis and neutralization. As a strong base, sodium hydroxide drives neutralizations, hydrolysis reactions, and pH-controlled syntheses. Plants buy at 50% and dilute in-line to the strength each reaction calls for.
• Soap production — saponification. Lye converts fats and oils into soap. Commercial soap makers work from 50% solution because it removes the dissolution step and gives a consistent, measurable alkali charge per batch.
• Food-industry processing. Sodium hydroxide is used in food-plant operations for pH control and as a cleaning agent in clean-in-place systems. Confirm on the lot documentation that this grade meets the requirements of your specific application before use.
• Textile processing. Mills use caustic in fabric treatment and preparation steps, where controlled alkalinity changes how fibers take up dyes and finishes.

Handling & Storage

Treat this product with the respect a Packing Group II corrosive demands. The GHS signal word is Danger, with hazard statements H290 (may be corrosive to metals) and H314 (causes severe skin burns and eye damage) (per the product's GHS classification). Full-coverage PPE is not optional: chemical splash goggles or a face shield, caustic-rated gloves, and an apron or suit rated for strong alkalis, with an eyewash and safety shower reachable from the work area.

Store it in corrosion-resistant containers — HDPE or stainless steel — in a cool, dry, ventilated area, away from acids and organic materials. Never store caustic above or beside acid inventory; a mixed spill is a violent neutralization. Keep containers closed and off bare concrete where a slow leak can go unnoticed. Because it is corrosive to metals (per the product's GHS classification), keep it away from aluminum, zinc, and galvanized fittings, which it attacks. This handling guidance is reviewed by Andre Taki, DOT Hazmat Specialist.

Hazmat & Shipping

This product ships as fully regulated hazmat, and we handle that for you. It moves under UN1824 (per 49 CFR 172.101), proper shipping name SODIUM HYDROXIDE SOLUTION (per 49 CFR 172.101), Hazard Class 8 — Corrosive (per 49 CFR 172.101), Packing Group II (per 49 CFR 172.101). Every shipment leaves Taylor, TX in UN-spec packaging with correct marks, labels, and shipping papers, prepared by a team that packs Class 8 corrosives every working day. We charge no hazmat fees — the price you see covers compliant packaging and paperwork.

Documentation

A Safety Data Sheet ships with every order, available in English, Spanish, French, and Japanese. A technical data sheet is available for spec review before you buy, and a lot-specific Certificate of Analysis is available so your QC team can verify the actual batch you receive, not a typical-values sheet.

Why Buy from Alliance Chemical

We are a chemical distributor and hazmat shipping operation, and this product is core inventory for us. It sits stocked in our Taylor, TX warehouse and ships daily — quarts and gallons for bench and pilot work, 5- to 55-gallon drums for plant use, and 275- and 330-gallon totes for bulk consumers. Every container goes out in DOT-compliant packaging with the SDS in the box and the paperwork done right, under guidance reviewed by a DOT Hazmat Specialist. When your process runs on caustic, the supplier's job is simple: the right concentration, properly packed, on time, every reorder. That is the job we do.