Sodium Oxymethylene (Formaldehyde) Sulfoxylate (SFS)



Rongalite is a chemical compound with the molecular formula Na+HOCH2SO2−. This salt has many additional names, including Rongalit, sodium hydroxymethylsulfinate, sodium formaldehyde sulfoxylate, and Bruggolite. It is listed in the European Cosmetics Directive as sodium oxymethylene sulfoxylate (INCI). It is water-soluble and generally sold as the dihydrate. The compound and its derivatives are widely used in the dye industry.



  • It has been used increasingly in commercial cosmetic hair dye colour removers
  • Industrial bleaching agent and as a reducing agent for vat dyeing
  • As a reducing agent in redox-initiator systems for emulsion polymerization
  • As water conditioner for aquaria as it rapidly reduces chlorine and chloramine and reacts with ammonia to form the innocuous aminomethylsulfinate ion
  • It is also used as an antioxidant in pharmaceutical formulation
  • It has a variety of specialized applications in organic synthesis