PyroSulphate

Causes severe irritation and burns. May Be harmful if swallowed. Avoid breathing vapor or dust. Use with adequate ventilation. Avoid contact with eyes, skin, and clothes. Wash thoroughly after handling. Keep container closed

Potassium pyrosulfate (potassium disulfate) is a chemical compound, K2S2O7. It contains the pyrosulfate anion S2O72− which has a dichromate like structure and can be visualised as two corner sharing SO4 tetrahedra, with a bridging oxygen atom.

Sodium pyrosulfate is a salt of sodium and pyrosulfate, obtained by the dehydration of sodium bisulfate. This is an intermediate stage in the preparation of sulfur trioxide.