Sodium sulfate

Sodium sulfate (CAS 15124-09-1) is an inorganic salt commercially known as salt cake, Glauber's salt, or natrii sulfas, with the molecular formula H2O4S.xNa. It is not assigned an E-number for food use in the EU and is distinct from sodium bisulfate or other sodium sulfur compounds.

In the pulp and paper industry, sodium sulfate functions as a makeup chemical in the kraft process, replenishing sulfur and sodium losses in the recovery cycle. In textile dyeing, it acts as a levelling agent by reducing the charge on cellulose fibres, slowing dye uptake and producing uniform colour distribution across the fabric.

Sodium sulfate is available in anhydrous fine powder form and supplied to industrial grades including technical and Ph.Eur.-compliant specifications. It falls under REACH regulation and requires a valid SDS for EU trade. Procurement quantities typically range from 25 kg bags to bulk.