Soda ash, also known as sodium carbonate, is an inorganic compound with the formula Na₂CO₃ and its various hydrates. It is a white, odorless, water-soluble salt that yields alkaline solutions in water. Soda ash has been used for over 5,000 years and is the 10th most consumed inorganic compound in the world. Historically, it was extracted from the ashes of plants grown in sodium-rich soils, which is why it became known as "soda ash". Today, it is produced in large quantities from sodium chloride and limestone by the Solvay process, as well as by carbonating sodium hydroxide which is made using the Chlor-alkali process.

Soda ash is used in a variety of applications, including:

• Dyeing: Soda ash is used with fiber-reactive dyes to produce brighter and more colorfast colors.

• Powdered detergents and soaps: Soda ash is a key component in the production of powdered detergents and soaps due to its high alkalinity and surfactant qualities, which allows it to improve cleaning performance.

When using soda ash for dyeing, it is important to handle it carefully. It is recommended to wear gloves and a mask while measuring out the powder to avoid skin exposure and breathing in any dust. If soda ash comes into contact with skin, it should be rinsed off immediately to avoid irritation.