Sodium carbonate

Sodium carbonate (CAS 497-19-8), commonly known as soda ash or washing soda, is an inorganic alkali. Also marketed as E500.

Where is Sodium carbonate used?

• Food manufacturing: acidity regulator and raising agent
• Glass manufacturing: lowers the melting point of silica, reducing energy costs in furnace operations
• Pulp and paper: pH regulation during chemical pulping and bleaching stages
• Water treatment: adjusts alkalinity to prevent pipe corrosion and support downstream coagulation processes
• Food and pharmaceutical formulating: leavening component, buffering agent, and pH modifier in solid and liquid systems
• It serves as a pH control agent, flux, and processing alkali in broader industry.
• As a food additive, acts as an acidity regulator, anti-caking agent and stabilizer.
• Raw material for producing sodium bicarbonate, sodium silicate and sodium phosphates.
• Neutralizes acidic wastewater and binds heavy metals in industrial processes in the chemical, metal and food industries.
• Used in cement and concrete additives such as superplasticizers, set accelerators and pH regulators.

Good to know: Soda ash dense and soda ash light are the two primary industrial forms, differing in bulk density and handling characteristics.

Formulation notes

• The anhydrous form offers higher active concentration, better storage stability, lower moisture sensitivity, and reliable processing in dry formulations.
• Soda ash light has lower density and faster dissolution rate than soda ash dense.

Typical specification

• Available in food grade as E 500 (i).
• Available as anhydrous (Soda leicht and Soda schwer), sodium carbonate-1-hydrate, sodium carbonate-10-hydrate (Soda calciniert), and powder form FG E 500 (i).
• Aqueous solutions are strongly alkaline, with pH 11.37 at 1 wt%, 11.58 at 5 wt%, and 11.70 at 10 wt% at 25°C.
• Soluble in water, with solubility increasing with temperature up to about 48.69 g/100 mL at 34.8 °C.
• Liquid sodium carbonate is supplied as a 16% solution.

Regulatory status

• Classified under the harmonised CLP classification according to Regulation 1272/2008 (CLP).
• Carries hazard statement H319, causing serious eye irritation.

Storage, packaging and handling

• Store tightly closed, dry, and at room temperature; retest period is 24 months.
• Absorbs moisture and carbon dioxide from air and converts to sodium bicarbonate.

Frequently asked questions about Sodium carbonate

What are the primary industrial uses of sodium carbonate?

Sodium carbonate is used to produce lithium carbonate for lithium-ion batteries, supporting e-mobility and energy storage applications.

How is sodium carbonate used in food processing?

It is used for the alkalization of cocoa powder to reduce bitterness and improve color and texture of chocolate products.

What role does sodium carbonate play in water treatment?

It is used as a softening agent to remove hardness from water.

Technical content is compiled and updated by the SoleChem product team from public technical sources; the certificate of analysis (COA) governs product-specific specifications.