Assay (Na2H2P2O7)..................................................................95,0-100,5%

Arsenic (as As), not more than........................................................ 3 ppm

Insoluble substances, not more than............................................... 0,6 %

Loss on drying at 105°C, not more than.......................................... 0,5 %

P2O5 content..............................................................................63,0-64 %

pH of 1%........................................................................................ 3,7-4,4

Fluoride, not more than................................................................. 10 ppm

Lead, not more than........................................................................ 2 ppm

Mercury, not more than................................................................... 1 ppm

Cadmium, not more than................................................................ 1 ppm