Many chemical properties of Sodium Metabisulfite or
sodium pyrosulfite make it a versatile compound useful in many applications.
Bisulfites are used in industries concerned with leather processing,
food and beverage processing, gas purification, water treatment to
remove excess chlorine, textiles and pulp processing, and many others.
a)
Leather Processing Industries (SMBS) : Sodium Metabisulfite is used
as leather processing chemical during the deliming process and helps to
prevent formation of toxiz hydrogen sulphide gas during deliming. It also
acts a bleaching agent. It makes leather soft, well-developed, tough
waterproof, anti-break, wear-ability and etc.
b)
Water Treatment Chemical : Sodium Metabisulfite plays an important
part in the treatment of water, wastewater and waste as a strong
reducing agent. Sodium Metabisulfite also assists in the dechlorination of
drinking water as well as in the chlorine removal in waste waters. Another
treatment method that utilizes Sodium Metabisulfite's effectiveness is in
the reduction of chromium.
Small water treatment plants use sodium bisulfite to remove chlorine from
the waste-water discharged back into lakes and rivers.
c)
Dye-industry : used as dechlorination agent and cotton boiling-off
agent for bleached cotton.
d)
Photographic Industry :
Sodium Metabisulfite's acidic and preservative properties also make it an
effective substitute for sodium bisulfite, a chemical which is used in
traditional darkroom photography.
e)
Rubber Industry : In rubber industry, it is used as coagulative
agent.
f)
Acrylic Sheets Manufacturing : It is used in manufacturing of
acrylic sheets.
g)
Water Pipes : The chemical is also used in the process of purifying
water, cleaning water pipes and reverse osmosis membranes in desalinization
equipment as it is an antibacterial. It is usually added to large piping
systems to prevent oxidative corrosion.
h)
Pharmaceutical Industries : Sodium Metabisulfite is an
antioxidant additive in injectable medicines and is lso used as a reducing
agent in pharmaceuticals.
i)
Chemical Industries : It is a common reducing agent in chemical
industries. Also, Sodium Metabisulfite is used as a bleaching agent in pulp
and textile manufacture. It is also a known preservative in cosmetics. The
chemical, in concentrated form, has also been used in landscape gardening as
a tree stump remover, as it disintegrates the lignin -- chemicals in plant
cell walls -- in the tree stumps, making them easier to remove.
j )
Wine & Beer Industry : 
It
is also present in wines and beers, as it is used as both a sterilizer and
an antioxidant in the process of brewing beer or fermenting wine. Sodium
metabisulphite is available in wine-making stores to sterilize and preserve
homemade wine. A small amount added to the pressed juice will kill any
alcohol-resistant mold that is on the fruit. It is used in almost all
commercial wines, to prevent oxidation and preserve flavor. In fruit
canning, sodium bisulfite is used to prevent browning (caused by oxidation)
and to kill microbes.
Sodium Metabisulfite is used as food processing chemical
to preserve color and inhibit bacterial growth on fruits and vegetables,
some seafood and in wine..
It can preserve many of the qualities of fruits and vegetables, including
the color, taste and nutritional value. It is a common ingredient used in
the canning process; the Sodium Metabisulfite protects the fruits and
vegetables from oxidizing and changing color.
It is used as a food preservative. It is commonly used as a food
preservative for dried foods, biscuits, potato chips, raisins and apples, as
well as fruit concentrate juices.It acts as an antimicrobial, inhibiting the
growth of fungi and bacteria, thereby keeping food fresh and safe.
It acts as a bleaching agent (Sweets , pastry, water-soaked bamboo slices,
etc.; It also acts as loosening agent (breads, biscuits, etc.); antioxygen
antistaling agent (acupuncture needle sprout, sea food, garden stuff, etc.)
For starch industry, Sodium metabisulfite is added to the
corn syrup as a preservative. It acts as a preservative agent.