Used as a reducing agent in textile printing, dyeing, and bleaching processes, particularly for vat dyes and sulfur dyes. It helps in solubilizing the dye by converting it to its leuco form, allowing better fabric penetration, and is often preferred over sodium hydrosulfite due to greater stability and safety for removing unwanted colors and enhancing whiteness.

Additionally, it serves as a catalyst in sulfomethylation processes and in the paper industry to bleach pulp for improved whiteness.

In polymer chemistry, it acts as an initiator or catalyst in radical polymerization reactions, particularly under acidic conditions.

It is also used in water treatment to remove chlorine or other oxidizing agents, as a stain remover or cleaner in various industries by reducing unwanted oxidizers, and in chemical synthesis for mild reductions that spare other functional groups.