Assay (as CaCO3) after drying...............................................98,0-100,5%

Acid insoluble substances, not more than....................................... 0,2 %

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

Fluoride, not more than................................................................ 0,005 %

Lead, not more than........................................................................ 3 ppm

Loss on drying, not more than......................................................... 2,0 %

Magnesium and alkali salts, not more than.........................................1 %

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

Antimony, Copper, Chromium, Zinc and Barium each one

or together, not more than...............................................................0,01%

Iron, not more than....................................................................... 0,001 %

Aluminium, not more than............................................................ 0,002 %