Chemical Specifications Appearance A soft, white or faintly yellowish white amorphous powder, free from grittiness Assay 99.0 - 100.5% Identification To pass IP test Substance insoluble in acid and carbonate To pass IP test Alkalinity To pass IP test Arsenic (As) Max. 0.0005% Iron (Fe) Max. 0.02% Lead (Pb) - as per IP To pass IP test Loss on ignition (at 500°C) Max. 1.0%