Spectrum Chemical manufactures and distributes fine chemicals with quality you can count on including those with CAS number 16731-55-8, Whether you call it Potassium Metabisulfite, Dipotassium Pyrosulfite or Potassium Pyrosulfite you can be assured the Potassium Metabisulfite products offered by Spectrum, meet or exceed the grade requirements or specifications for each individual product.