In combination with sodium hydrosulphite it is used as a rust-stain remover.

It is used in photography.

It is also used as an excipient in some tablets, such as paracetamol.

A very important health related aspect of this substance is that it can be added to a blood smear in a test for sickle cell anaemia. The substance causes defunct cells to sickle (through a complex polymerisation) hence confirming disease.

It is used as a bleaching agent in the production of coconut cream

It (or liquid SO₂) is commonly used as an antimicrobial and antioxidant in winemaking.

It is used as a reducing agent to break sulphide bonds in shrunken items of clothing made of natural fibres, thus allowing the garment to go back to its original shape after washing.

It is used as an SO₂ source (mixed with air or oxygen) for the destruction of cyanide in commercial gold cyanidation processes

It is used in the water treatment industry to quench residual chlorine.

It is used as a fungicide for anti-microbe and mould prevention during shipping of consumer goods such as shoes and clothing. Plastic stickers and packaging containing the anhydrous, sodium metabisulfite solid active ingredient are added prior to shipping.

It is used for preserving fruit during shipping.

It is used as a solvent in the extraction of starch from tubers, fruit and cereal crops.

It is used as a pickling agent to treat high pressure reverse osmosis and nanofiltration water desalination membranes for extended storage periods between uses.

SAFETY/CAUTION–Sodium metabisulfite, despite not being flammable, decomposes in 150°C of heat releasing toxic gasses when decomposed. It is corrosive when dissolved in water.

It is harmful if swallowed, is corrosive to metals and should be stored carefully.