Sodium sulfide

Sodium sulfide (CAS 1313-82-2, EC 215-211-5, Na2S), also known as disodium sulfide or sodium monosulfide, is an inorganic sulfur compound supplied in flake form. It carries no E-code designation and is not classified as a food additive.

In leather processing, sodium sulfide breaks disulfide bonds in keratin to remove hair from hides during the unhairing stage. In mining, it acts as a selective depressant and collector in froth flotation, separating sulfide ores from gangue. Water treatment applications rely on its reducing properties to precipitate heavy metal ions as insoluble sulfides.

Sodium sulfide is available in technical grade, with purity levels typically expressed as Na2S content ranging from 60 to 62 percent. The substance is registered under REACH and subject to classification under CLP regulation as corrosive and environmentally hazardous. It is commonly supplied in sealed polyethylene-lined drums or bulk bags to limit oxidation and moisture uptake.