Sodium Hydroxide, also known as caustic soda, lye, or sodium hydrate, is a very strong and highly caustic alkaline chemical widely used in industrial manufacturing, cleaning, and water treatment. Its CAS number is 1310-73-2.
In pure form, sodium hydroxide is a white, odorless, crystalline solid. It is extremely soluble in water, and when dissolved, it produces a highly exothermic reaction (releases heat). Because it reacts strongly with water, CO₂, acids, aluminum, and many metals, it must be stored in dry, airtight containers.
Chemically, it is one of the strongest bases available. It has a very high pH, is highly reactive, and can break down organic material, fats, oils, and proteins. This is why it is used in soap-making (saponification), drain cleaners, oven cleaners, and strong industrial degreasers.
Sodium hydroxide is sold in several forms, such as flakes, pearls (pellets), granules, or liquid solutions (commonly at 20%, 32%, 45%, or 50% concentration).
It is widely used in many industries. In the chemical industry, it is used for pH adjustment, neutralization, and synthesis of detergents, surfactants, and other chemicals. In water treatment, it is used to adjust pH and help with coagulation and impurity removal. In food processing, food-grade sodium hydroxide is used for cleaning, sanitation, olive curing, cocoa processing, and peeling fruits/vegetables. In pulp and paper, it plays a critical role in the kraft pulping process. It is also used in pharmaceutical and petrochemical applications.
Because sodium hydroxide is highly corrosive, it can cause severe burns to skin, eyes, and respiratory tissue. Proper handling requires protective gloves, goggles, and protective equipment. It must be used in well-ventilated areas, and contact with moisture or incompatible materials must be avoided.
