Sodium sulfate

Sodium sulfate (CAS 7757-82-6), also known as sodium sulphate, is an inorganic salt sourced in anhydrous form.

Where is Sodium sulfate used?

• Detergent manufacturing: filler and flow-control agent in powdered formulations, improving bulk density and dispensing consistency; used in the detergent industry at a level of 25% by weight.
• Kraft pulp mills: make-up chemical.
• Sulfate pulping: maintains the chemical balance of the recovery cycle.
• Textile dyeing: regulates dye uptake on cellulosic fibers, improving color uniformity.
• In pharmaceutical solid-dose manufacturing it serves as an excipient and desiccant component for moisture control.
• In molten glass, it dissolves gas bubbles to produce a clearer material.
• Lowers the melting point of ceramic raw materials, saving energy and improving sintering stages.
• In pharmacology, the decahydrate form (Glauber's salt) is registered as an osmotic laxative (European Pharmacopoeia) and is used in bowel preparation before endoscopic procedures.

Formulation notes

• The anhydrous salt (CAS 7757-82-6) is the drying agent used in the laboratory, while the decahydrate or Glauber's salt (CAS 7727-73-3) is the hydrated form used in pharmacology as an osmotic laxative.
• Unlike sodium chloride, it does not damage stainless steel vessels, making it a safer option for machinery.
• Contact with strong acids or bases should be avoided because it can trigger undesirable reactions.

Typical specification

• The content (assay) is at least 99.5%.
• Chloride content is at most 0.01%.
• Iron content is at most 10 ppm.
• Water content is at most 0.1%.

Regulatory status

• Anhydrous sodium sulfate is not classified as hazardous under Regulation (EC) 1272/2008 (CLP).
• Sodium sulfate (CAS 7757-82-6) is covered by the OECD SIDS assessment for High Production Volume Chemicals.
• Sodium sulfate is an authorized food additive (E514), used as an acidity regulator and as a carrier for colorants.

Storage, packaging and handling

• Must be stored in dry places to prevent it from absorbing moisture.
• Packaged in plastic sacks of 25 kg, supplied as 40 sacks per unit.

Frequently asked questions about Sodium sulfate

What is the role of sodium sulfate in the paper cycle?

It balances pH and supports cleaning and flocculation processes in the paper cycle.

How is sodium sulfate used in laboratory chemical analysis?

It is an effective drying agent for organic solvents, absorbing water of crystallization to dehydrate organic extracts before filtration and evaporation.

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