Caustic Soda Flakes, also known as solid sodium hydroxide (NaOH), is a highly caustic, strong alkaline compound appearing as white flakes. It is produced by evaporating a 50% caustic soda (liquid NaOH) solution.
This material reacts vigorously with acids, light metals, water, oils, and fats, and is widely used across chemical, petrochemical, detergent, food, textile, and oil & gas industries.

Chemical Structure of Caustic Soda Flakes

Chemical Name: Sodium Hydroxide
Chemical Formula: NaOH
Ionic Structure: Na⁺ and OH⁻ ions in an orthorhombic crystal lattice
CAS Number: 1310-73-2
EC Number: 215-185-5
Molecular Weight: 40.00 g/mol

Physical and Chemical Properties

Property	Description
Physical State	White solid flakes
Melting Point	318°C
Boiling Point / Decomposition	1,388°C (decomposes to Na₂O and H₂O at high temperatures)
Density	2.13 g/cm³
pH (1% aqueous solution)	13 – 14
Solubility in Water	Highly soluble; exothermic reaction upon dissolution
Reactivity	Extremely reactive with water, acids, and light metals (e.g., aluminum, zinc) – releases flammable hydrogen gas
Odor / Viscosity	Odorless; non-viscous (solid form)

Applications of Caustic Soda Flakes

Detergent and Cleaning Industries

Manufacturing of solid and liquid soaps, dishwashing liquids, degreasers, bleaches, and disinfectants
Fat and oil removal in industrial wastewater treatment

Oil, Gas, and Petrochemical Industries

Neutralization of acids in various processes
Sweetening of crude oil and natural gas (removal of H₂S and CO₂)
Regeneration of ion-exchange resins

Pulp, Paper, and Textile Industries

Used in the Kraft process for separating cellulose fibers from wood
pH control during dyeing, washing, and bleaching

Food Industry (Food Grade – E524)

CIP (Cleaning in Place) for pipelines and storage tanks
Used in chocolate, ice cream, soft drinks, and olive curing (in very small, controlled doses)

Metal and Surface Treatment

Polishing and etching of aluminum surfaces
Metal extraction from ores
Scale removal and cleaning of industrial equipment

Advantages of Caustic Soda Flakes

Highly effective in neutralizing acids and fats
Low cost and readily available in bulk quantities
Versatile – applicable across numerous industries
Long-term stability when stored in dry conditions
Flake form allows for easier handling, dosing, and storage

Disadvantages of Caustic Soda Flakes

Highly corrosive to skin, eyes, and many metals
Exothermic reaction with water → risk of chemical burns
Hygroscopic – absorbs moisture from the air, leading to caking
Requires alkali-resistant equipment for handling and transfer
Corrosive to seals, valves, and light metal fittings

Safety and Handling Information

GHS Classification: Corrosive – H314 (Causes severe skin burns and eye damage) – GHS Class 8
Personal Protective Equipment (PPE):
- Gloves: Neoprene or PVC
- Eye Protection: Safety goggles or face shield
- Respiratory Protection: Mask or respirator for dust exposure
- Clothing: Alkali-resistant lab coat or apron
First Aid Measures:
- Skin/Eye Contact: Rinse immediately with plenty of water (at least 15 minutes) and seek medical attention
- Inhalation of Dust: Ensure proper ventilation; use filter respirator in enclosed areas

Storage and Compatibility

Parameter	Recommended Condition
Storage Environment	Cool, dry, well-ventilated area
Packaging	Moisture-proof triple-layer polypropylene bags (typically 25 kg)
Compatibility	Keep away from acids, light metals, nitrogenous and halogenated organic compounds
Handling Precautions	Avoid contact with water; prevent exposure to moisture and humidity

Packaging and Transport

Standard Packaging: 25 kg moisture-resistant PP bags with inner liner
Transportation: Non-flammable but classified as Corrosive (GHS Class 8) — handle with appropriate labeling and containment