Question

What is the role of sodium metabisulfite in cosmetics?

Answer 1

Sodium Meta Bisulphate Na2 S2 O6 is not used in cosmetics.  It is Sodium Meta Bisulphite Na2 S2 O5 which is used in cosmetics. 

    It is a good disinfectant. It is chemically a good reducing agent or antioxidant. It can donate Hydrogen ions to other compounds.  It is a good preservative too. So it is used on hair primarily to protect hair. 

  Sodium Meta Bisulphite is used to make many cosmetic products due to its chemically reactive properties.