Product Overview
Sodium Hydroxide Flakes are a strong inorganic base supplied in solid flake form under CAS 1310-73-2. This Technical Grade product — also known as caustic soda or NaOH — dissolves readily in water and generates significant heat on contact, making it one of the most widely used alkalis in industrial processing. It is classified as a Class 8 corrosive for transport (per 49 CFR 172.101), which shapes every step of how we package, label, and ship it from our Taylor, TX facility.
This product is offered in sizes ranging from 2 lb units suited for bench-scale work and small soap-making batches up through 55 lb quantities built for continuous production lines, water treatment systems, and chemical manufacturing operations.
Lye turns grease into soap; baking soda and vinegar mostly react with each other. The chemistry of a grease clog.
Why Technical Grade Flakes
Technical Grade sodium hydroxide flakes are the workhorse choice for operations where the primary requirement is a strong, cost-effective alkali — pH adjustment in municipal or industrial water systems, soap and detergent manufacturing, chemical synthesis, and general cleaning or degreasing. Buyers who need the dissolving control of a dry solid rather than a premixed solution choose flakes: you proportion the exact strength your process demands by dissolving flakes into your own water at the ratio you set.
The solid flake form also simplifies storage logistics. Unlike liquid caustic, flakes do not freeze-solidify in winter transit, they occupy less freight volume per unit of active NaOH, and they have essentially zero vapor pressure — meaning minimal off-gassing in a sealed container. The trade-off is the exothermic dissolving step: operators must add flakes to water (never the reverse) with continuous stirring and appropriate PPE, because the dissolution reaction produces enough heat to boil small volumes of water if the ratio is too aggressive.
Chemical Profile
Sodium hydroxide flakes are a white, odorless solid with the molecular formula NaOH and a molecular weight of 39.997 g/mol (CAS 1310-73-2). The bulk solid has a density of approximately 1.5 at 68 °F — substantially denser than water. Solubility is exceptionally high at 111%, meaning sodium hydroxide absorbs moisture from air and will readily dissolve well beyond a 1:1 weight ratio in water. Vapor pressure is essentially zero (approximately 0 mmHg), so the dry flake produces no significant vapor under normal storage conditions. This hygroscopic character is why sealed, moisture-proof packaging matters — open containers will cake and clump as the flakes draw humidity from ambient air.
Industrial Applications
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pH Control & Water Treatment — Sodium hydroxide flakes dissolve into process water to neutralize acidic streams and raise pH to target setpoints. Municipal plants, cooling towers, and industrial effluent systems dose NaOH solutions to meet discharge permits and protect downstream equipment from acid corrosion.
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Soap Making & Saponification — NaOH is the classic alkali for cold-process and hot-process soap production. Flakes dissolve into a lye solution at a measured concentration, then react with fats and oils to form solid bar soap. The flake format gives soap makers precise control over lye strength — critical for consistent bar hardness and cure time.
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Chemical Manufacturing — Sodium hydroxide serves as a primary reactant and pH modifier in the production of detergents, textiles, paper pulp, and a wide range of downstream sodium salts. Large-scale operations consume NaOH in bulk as a feedstock alkali.
Handling & Storage
Sodium hydroxide flakes carry the signal word Danger (per the product's GHS classification). The governing hazard statements are H290 — may be corrosive to metals — and H314 — causes severe skin burns and serious eye damage (per the product's GHS classification). These are not boilerplate warnings: dry NaOH will cause immediate tissue damage on skin contact, and dissolved NaOH at working concentrations is severely corrosive.
Required PPE for any handling operation includes chemical-splash goggles (not safety glasses), face shield, chemical-resistant gloves (neoprene or butyl rubber), and a long-sleeved chemical apron or suit. When dissolving flakes, work in a well-ventilated area and add flakes slowly to water — never pour water onto flakes — while stirring continuously to dissipate heat.
Store containers sealed and upright in a cool, dry area away from acids, aluminum, zinc, tin, and other amphoteric metals. NaOH reacts vigorously with acids and generates hydrogen gas on contact with certain metals. Because the flakes are hygroscopic, even brief exposure to humid air will cause caking. Once opened, reseal immediately or transfer to an airtight container.
Hazmat & Shipping
Sodium hydroxide flakes ship under a full DOT hazmat classification:
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UN Number: UN1823 (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, solid (per 49 CFR 172.101)
Every outbound shipment from our Taylor, TX warehouse is labeled, marked, and placarded to 49 CFR requirements. Shipping papers with the correct UN entry accompany each package. Class 8 corrosive materials require segregation from certain other hazard classes during transport — our warehouse team stages and loads to those separation tables daily.
Documentation
A Safety Data Sheet ships with every order, available in English, Spanish, French, and Japanese. A lot-specific Certificate of Analysis is available on request, documenting the analytical results for the batch you receive. A Technical Data Sheet is also on file for reference. If you need any of these documents before placing an order, contact our team and we will send them directly.
Why Buy from Alliance Chemical
Sodium hydroxide flakes are a Class 8 corrosive solid — UN1823, Packing Group II — and every unit that leaves our warehouse ships with correct DOT hazmat labeling, separation, and documentation. That is not a courtesy; it is what a USDOT-registered hazmat shipper (registration #2188383) does on every order. Alliance Chemical has operated since 1998 and has served more than 55,000 customers across industrial, municipal, and specialty markets. Shipping and handling guidance on this page has been reviewed by Andre Taki, DOT Hazmat Specialist.
Comparing suppliers?
Before you compare quotes, read How to Choose a Bulk Chemical Supplier — the four documents to demand, how to pick the grade your process actually needs (and where buyers overpay), why you should compare delivered prices rather than unit prices, and the red flags worth walking away from.
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.
Related Reading
Seoul prosecutors allege six Korean makers fixed the prices of caustic soda, hydrochloric acid, hypochlorite and chlorine for the Korean market and sent their price-increase notices in a pre-arranged order. How that compares with the US DOJ warning signs, what EPA trade data says about US exposure, and what to keep on file when you compare quotes. Prosecutors Say Korea’s Chlor-Alkali Makers Took Turns Sending Price Notices.
