EghtesadOnline: Caustic soda, or sodium hydroxide, is one of the most important chemicals manufactured. Sodium hydroxide, also known as Caustic Soda is a highly caustic metallic base. It is a white solid available in pellets, flakes, granules, and as a 50% saturated solution. Sodium hydroxide is soluble in water, ethanol and methanol. This alkali is deliquescent and readily absorbs moisture and carbon dioxide in air.