{"product_id":"sodium-hydroxide-50-membrane-grade-caustic-soda-lye","title":"Sodium Hydroxide 50% Membrane Grade (Caustic Soda, Lye)","description":"\u003ch2\u003eProduct Overview\u003c\/h2\u003e\u003cp\u003eSodium Hydroxide 50% Membrane Grade (Caustic Soda, Lye) is a highly concentrated, strongly alkaline liquid solution engineered for demanding industrial processes. This chemical intermediate, with molecular formula HNaO and molecular weight 39.997, plays an essential role in numerous chemical manufacturing, water treatment, and neutralization applications. As a premier industrial distributor, Alliance Chemical provides this high-purity solution to facilitate efficient processing across diverse sectors. Our 50% concentration provides a balance between high chemical activity and convenient liquid handling, eliminating the need to dissolve solid beads or flakes on-site.\u003c\/p\u003e\u003cp\u003eMaintaining consistent concentration and purity is critical for industrial workflows. Our Sodium Hydroxide 50% solution is colorless and more dense than water, exhibiting strong alkalinity even in a 1% dilution. We ensure that every batch conforms strictly to chemical specifications to prevent unwanted process deviations. Safety Data Sheets (SDS) are provided with every order to ensure safe handling, and a Certificate of Analysis (COA) is always available upon request. Customers can easily find related alkaline compounds by visiting our \u003ca href=\"\/collections\/bases\"\u003eBases collection\u003c\/a\u003e to source compatible raw materials for their operations.\u003c\/p\u003e\u003ch3\u003eWhy This Grade\u003c\/h3\u003e\u003cp\u003eMembrane grade sodium hydroxide represents the highest standard for commercial liquid caustic soda, characterized by extremely low concentrations of salt (sodium chloride), chlorates, and carbonate impurities. This ultra-pure grade is produced using modern membrane cell electrolysis, which avoids the heavy metal contamination historically associated with mercury cells or the higher salt content typical of diaphragm cell processes. For industries like pulp and paper, textile manufacturing, and specialty chemical synthesis, utilizing membrane grade is necessary to protect sensitive catalytic systems and prevent unwanted secondary chemical reactions.\u003c\/p\u003e\u003cp\u003eChoosing the incorrect grade or concentration of sodium hydroxide can lead to severe operational failures. Standard industrial-grade caustic soda often contains elevated levels of chloride and silica, which can cause rapid corrosion of stainless steel process piping and scale buildup in heat exchangers. Furthermore, using a lower concentration than 50% increases transportation costs per unit of active chemistry and alters the water balance in closed-loop chemical reactions. By selecting our Membrane Grade 50% solution, operators ensure maximum efficiency, minimize the risk of equipment fouling, and maintain precise control over their reaction stoichiometry.\u003c\/p\u003e\n\u003cdiv class=\"chemical-profile\" data-source=\"canonical\"\u003e\n\u003ch3\u003eChemical Profile\u003c\/h3\u003e\n\u003cdl\u003e\n\u003cdt\u003eCAS Number\u003c\/dt\u003e\n\u003cdd\u003e1310-73-2\u003c\/dd\u003e\n\u003cdt\u003eChemical Formula\u003c\/dt\u003e\n\u003cdd\u003eHNaO\u003c\/dd\u003e\n\u003cdt\u003eMolecular Weight\u003c\/dt\u003e\n\u003cdd\u003e39.997 g\/mol\u003c\/dd\u003e\n\u003cdt\u003eBoiling Point\u003c\/dt\u003e\n\u003cdd\u003egreater than 266 °F at 760 mmHg (USCG, 1999)\u003c\/dd\u003e\n\u003cdt\u003eMelting Point\u003c\/dt\u003e\n\u003cdd\u003e604 °F (USCG, 1999)\u003c\/dd\u003e\n\u003cdt\u003eFlash Point\u003c\/dt\u003e\n\u003cdd\u003eN\/A °C\u003c\/dd\u003e\n\u003cdt\u003eSpecific Gravity\u003c\/dt\u003e\n\u003cdd\u003e1.5 at 68 °F (USCG, 1999) - Denser than water; will sink\u003c\/dd\u003e\n\u003cdt\u003eAppearance\u003c\/dt\u003e\n\u003cdd\u003eSodium hydroxide solution appears as a colorless liquid. More dense than water. Contact may severely irritate skin, eyes, and mucous membranes. Toxic by ingestion. Corrosive to metals and tissue.\u003c\/dd\u003e\n\u003cdt\u003eSolubility\u003c\/dt\u003e\n\u003cdd\u003e111 % (NIOSH, 2024)\u003c\/dd\u003e\n\u003cdt\u003eUN Number\u003c\/dt\u003e\n\u003cdd\u003eUN1824\u003c\/dd\u003e\n\u003cdt\u003eHazard Class\u003c\/dt\u003e\n\u003cdd\u003eClass 8\u003c\/dd\u003e\n\u003cdt\u003ePacking Group\u003c\/dt\u003e\n\u003cdd\u003eII\u003c\/dd\u003e\n\u003cdt\u003eProper Shipping Name\u003c\/dt\u003e\n\u003cdd\u003eSODIUM HYDROXIDE SOLUTION\u003c\/dd\u003e\n\u003cdt\u003eGHS Signal Word\u003c\/dt\u003e\n\u003cdd\u003eDanger\u003c\/dd\u003e\n\u003c\/dl\u003e\n\u003cp class=\"chemical-profile__note\"\u003e\u003cem\u003eValues sourced from Alliance Chemical's canonical chemistry registry. Certificate of Analysis (COA) per lot.\u003c\/em\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\u003ch3\u003eIndustrial Applications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eChemical Synthesis: Serves as a primary alkaline reactant and pH regulator in the production of diverse organic and inorganic chemicals, including plastics, synthetic fibers, and sodium salts.\u003c\/li\u003e\n\u003cli\u003ePulp and Paper Processing: Utilized in the Kraft process for de-inking recycled fibers, bleaching wood pulp, and treating process water to maintain optimal digestion alkalinity.\u003c\/li\u003e\n\u003cli\u003eWater and Wastewater Treatment: Employed to adjust pH levels, neutralize acidic effluent streams, and precipitate heavy metals from industrial wastewater discharges before environmental release.\u003c\/li\u003e\n\u003cli\u003eTextile and Mercerizing: Applied in the mercerization process of cotton fibers to increase luster, improve tensile strength, and enhance dye affinity in industrial textile manufacturing.\u003c\/li\u003e\n\u003cli\u003eMetal Cleaning and Etching: Used in metalworking to clean surface oils, degrease components, and perform controlled etching on aluminum surfaces during anodizing preparations.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eHazmat \u0026amp; Shipping\u003c\/h3\u003e\u003cp\u003eSodium Hydroxide 50% Membrane Grade is classified as a regulated hazardous material due to its highly corrosive properties. For transport, it is designated as \u003cstrong\u003eUN1824\u003c\/strong\u003e, Hazard Class \u003cstrong\u003e8\u003c\/strong\u003e, with a Packing Group of \u003cstrong\u003eII\u003c\/strong\u003e, and the proper shipping name \u003cstrong\u003eSODIUM HYDROXIDE SOLUTION\u003c\/strong\u003e. The signal word for this chemical is \u003cstrong\u003eDanger\u003c\/strong\u003e. There are no GHS pictograms applicable in the authoritative record for this specific configuration. Compliance with Department of Transportation (DOT) regulations is strictly observed in every shipment we dispatch from our Texas facilities to guarantee secure delivery.\u003c\/p\u003e\u003cp\u003eThe hazard statements associated with this product are H290 (May be corrosive to metals) and H314 (Causes severe skin burns and eye damage). Proper safety measures are required under OSHA regulations. Personnel handling this substance must utilize appropriate Personal Protective Equipment (PPE) to mitigate risks. This includes chemical-resistant gloves, protective clothing, and a face shield. The primary precautionary statements to follow include P234 (Keep only in original packaging), P260 (Do not breathe mist or vapors), P280 (Wear protective gloves\/clothing\/eye protection), and P305+P351+P338 (In case of contact with eyes, rinse cautiously with water). For additional details on safe handling, explore our \u003ca href=\"\/products\/sodium-hydroxide-50-membrane-grade-caustic-soda-lye\"\u003eSodium Hydroxide 50% product page\u003c\/a\u003e to review material safety guidelines.\u003c\/p\u003e\u003ch3\u003eHandling \u0026amp; Storage\u003c\/h3\u003e\u003cp\u003eProper storage is essential to prevent operational issues. Sodium hydroxide solutions of 50% concentration will begin to crystallize or freeze at approximately 54°F (12°C). Therefore, storage tanks and piping must be heat-traced or maintained in temperature-controlled environments to prevent freezing. Standard container materials should include high-density polyethylene (HDPE), polypropylene, or nickel alloys. Avoid any contact with aluminum, zinc, tin, or galvanized metals, as caustic soda reacts with these materials to generate flammable hydrogen gas. Keep containers tightly closed and isolated from strong acids and organic halogens.\u003c\/p\u003e\u003ch3\u003eOrder \u0026amp; Documentation\u003c\/h3\u003e\u003cp\u003eAlliance Chemical ensures that every customer receives the documentation required for strict regulatory and quality compliance. We provide comprehensive logistic support for quantities ranging from quarts to bulk drums. A Safety Data Sheet (SDS) is provided with every order, and a Certificate of Analysis (COA) is always available upon request to verify physical and chemical properties. To proceed with your procurement, please use our online tools to \u003ca href=\"\/pages\/contact\" class=\"cta-button\"\u003eRequest a Quote\u003c\/a\u003e or \u003ca href=\"\/pages\/safety-data-sheets\"\u003eDownload the SDS\u003c\/a\u003e.\u003c\/p\u003e\u003ch3\u003eWhy Buy from Alliance Chemical\u003c\/h3\u003e\u003cp\u003eSince 1997, Alliance Chemical has supplied premium industrial chemicals from Taylor, Texas under CAGE Code 1LT50, with a COA and SDS included on every order. For industrial use only.\u003c\/p\u003e\u003cdiv style=\"margin:2.4rem 0 1rem;padding:1.2rem 1.4rem;background:#f7f6ff;border-left:4px solid #5F59F7;border-radius:6px;\"\u003e\n\u003cp style=\"margin:0 0 .35rem;font-family:'JetBrains Mono',ui-monospace,monospace;font-size:.72rem;letter-spacing:.10em;text-transform:uppercase;color:#5F59F7;font-weight:600;\"\u003eRelated reading\u003c\/p\u003e\n\u003cp style=\"margin:0;font-size:1rem;line-height:1.55;color:#1A1040;\"\u003e\u003ca href=\"https:\/\/alliancechemical.com\/blogs\/articles\/car-dipping-3-tank-paint-rust-removal-process-guide\" style=\"color:#1A1040;font-weight:600;text-decoration:underline;text-decoration-thickness:1.5px;text-underline-offset:2px;\"\u003eCar Dipping: The 3-Tank Process That Strips Paint and Kills Rust on a Whole Car Body\u003c\/a\u003e — restoration shops use NaOH 50% Membrane Grade diluted to 25–30% as the hot Tank 1 caustic bath in the 3-tank car dipping process.\u003c\/p\u003e\n\u003c\/div\u003e\u003cdiv class=\"ac-product-guide-callout\" style=\"margin:2rem 0 1rem;padding:1.25rem 1.5rem;background:#f8fafc;border:1px solid #e2e8f0;border-left:4px solid #0891b2;border-radius:0.5rem;\"\u003e\n\u003cp style=\"margin:0 0 0.5rem;font-size:0.72rem;font-weight:700;letter-spacing:0.12em;text-transform:uppercase;color:#0891b2;\"\u003eCo-Dose Application\u003c\/p\u003e\n\u003cp style=\"margin:0 0 0.65rem;font-size:1.05rem;font-weight:600;color:#0d2137;line-height:1.4;\"\u003eUsing this product with alum for industrial wastewater pH control\u003c\/p\u003e\n\u003cp style=\"margin:0 0 0.85rem;font-size:0.95rem;line-height:1.55;color:#1a1a2e;\"\u003eCaustic soda is the standard co-dose partner for Aluminum Sulfate 50% in industrial wastewater treatment — the alkaline neutralizer that holds pH in the 5.5–7.5 coagulation sweet spot as the acidic alum drives pH downward. Read our complete technical guide on the chemistry, jar-testing protocol, and EPA 40 CFR 433 compliance framework.\u003c\/p\u003e\n\u003ca href=\"\/blogs\/articles\/aluminum-sulfate-metal-fabrication-wastewater-treatment\" style=\"display:inline-block;background:#0891b2;color:#fff;padding:8px 18px;border-radius:6px;text-decoration:none;font-weight:600;font-size:0.92rem;\"\u003eRead the technical guide →\u003c\/a\u003e\n\u003c\/div\u003e","brand":"Alliance Chemical","offers":[{"title":"1 Quart \/ 1 Quart","offer_id":41291559075882,"sku":"K4-KN5I-VEP0","price":25.3,"currency_code":"USD","in_stock":true},{"title":"1 Quart \/ 2 Quarts","offer_id":41291576016938,"sku":"QGP-T4L-Z9C","price":30.8,"currency_code":"USD","in_stock":true},{"title":"1 Quart \/ 4 Quarts","offer_id":41374815813674,"sku":"0Z-XVMN-TBLT","price":33.0,"currency_code":"USD","in_stock":true},{"title":"1 Quart \/ 8 Quarts","offer_id":41374815846442,"sku":"2XY-A0L-A24","price":51.7,"currency_code":"USD","in_stock":true},{"title":"1 Gallon \/ 1 Gallon","offer_id":41291576049706,"sku":"916-48B-4C4","price":33.0,"currency_code":"USD","in_stock":true},{"title":"1 Gallon \/ 2 Gallons","offer_id":41374815879210,"sku":"DCT-P2W-C1Z","price":51.7,"currency_code":"USD","in_stock":true},{"title":"1 Gallon \/ 4 Gallon Case","offer_id":41291576082474,"sku":"0U-0V54-C1W6","price":98.8,"currency_code":"USD","in_stock":true},{"title":"1 Gallon \/ 4 Gallons x 36 Cases","offer_id":41891045736490,"sku":"PGF-ELK-XXP","price":1839.02,"currency_code":"USD","in_stock":true},{"title":"5 Gallon \/ 5 Gallon Pail","offer_id":41291576148010,"sku":"QO-I0C4-DD9R","price":121.0,"currency_code":"USD","in_stock":true},{"title":"5 Gallon \/ 4 x 5 Gallon Pails","offer_id":41374815911978,"sku":"TQ9-1U2-1HS","price":425.92,"currency_code":"USD","in_stock":true},{"title":"5 Gallon \/ 36 x 5 Gallons (Pallet)","offer_id":41884775317546,"sku":"TNF-QLU-5MF","price":2275.79,"currency_code":"USD","in_stock":true},{"title":"15 Gallon \/ 15 Gallon Drum","offer_id":41291576213546,"sku":"IDH-UWO-HEG","price":341.14,"currency_code":"USD","in_stock":true},{"title":"55 Gallon \/ 55 Gallon Drum","offer_id":41291576246314,"sku":"BM-TNEN-1FTW","price":709.5,"currency_code":"USD","in_stock":true},{"title":"55 Gallon \/ 4 x 55 Gallon Drums","offer_id":41291576279082,"sku":"SE8-CCT-SFB","price":2497.44,"currency_code":"USD","in_stock":true},{"title":"275 Gallon \/ 275 Gallon IBC Tote","offer_id":41884775350314,"sku":"4MF-7GT-M8M","price":3090.58,"currency_code":"USD","in_stock":true},{"title":"330 Gallon \/ 330 Gallon IBC Tote","offer_id":43829839822890,"sku":"GIJ-OU9Q-YX5","price":3491.4,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0588\/2734\/1866\/files\/Sodium-Hydroxide-50-Quart_a719f539-8417-4bdc-bfdf-65f9f14ac085.jpg?v=1748983651","url":"https:\/\/alliance-chemical-store.myshopify.com\/products\/sodium-hydroxide-50-membrane-grade-caustic-soda-lye","provider":"Alliance Chemical","version":"1.0","type":"link"}