At room temperature, sodium hydroxide is a white crystalline odorless solid that absorbs moisture from the air. It is a manufactured substance. When dissolved in water or neutralized with acid it liberates substantial heat, which may be sufficient to ignite combustible materials. Sodium hydroxide is very corrosive. It is generally used as a solid or a 50% solution. Other common names include caustic soda and lye.Sodium hydroxide is used to manufacture soaps, rayon, paper, explosives, dyestuffs, and petroleum products. It is also used in processing cotton fabric, laundering and bleaching, metal cleaning and processing, oxide coating, electroplating, and electrolytic extracting. It is commonly present in commercial drain and oven cleaners

1. Mainly used in papermaking, production of cellulose pulp, manufacture of soap, synthetic detergents, synthetic fatty acids, and refining of animal and vegetable oils. In textile printing and dyeing industry, it is used as desizing agent, scouring agent and mercerizing agent for cotton fabrics.

2. In chemical industry, used for production of borax, sodium cyanide, formic acid, oxalic acid, phenol, etc.

3. In petroleum industry, used for refining petroleum products and in oilfield drilling mud. Also used for production of aluminum oxide, surface treatment of zinc and copper metals, as well as in glass, enamel, leather, pharmaceuticals, dyes and pesticides.

4. Food-grade product is used as acid neutralizer in food industry, can be used as peeling agent for citrus, peaches, etc., also as detergent for empty bottles, cans and other containers, as well as decolorizing agent and deodorizing agent.

5. As a basic reagent, sodium hydroxide can be used as neutralizer, complex masking agent, precipitant, precipitation masking agent, absorbent for trace carbon dioxide and water, color reagent for determination of ketosteroids by thin-layer chromatography, etc. It is widely used in manufacturing various sodium salts, soap, paper pulp, finishing cotton fabrics, silk, viscose fibers, recycling of rubber products, metal cleaning, electroplating, bleaching, etc.

6. In cosmetic creams, sodium hydroxide saponifies with stearic acid and acts as emulsifier for the production of vanishing cream, shampoo, etc.