Appearance: White crystals
Purity (H3PO3): 98% min
Phosphates (PO43-): 0.1% max.
Chlorides (Cl-): 0.01% max.
Sulfates(SO42-): 0.006% max
Heavy Metal (as Pb): 0.001% max.
Ferrous (Fe): 0.005% max.

colourless crystal. specific gravity:1.651. melting point: 74?. boiling point: 200?. strongly absorb moisture in air and soluable in water and alcohol.