Name of indexes	FCC-IV	USP-23
Appearance	Whitish powder	Whitish powder
Assay (As CaHPO4), %	97.0-105.0	98.0-105.0
Fluoride, ≤%	0.005	0.005
Loss on drying, ≤%	7.0-8.5	6.6-8.5
Heavy metals(As Pb), ≤%	0.0015	0.0015
Pb, ≤%	0.0002	-
As, ≤%	0.0003	0.0003
Insolubles in HCI, ≤%	-	0.2
Chloride, ≤%	-	0.25
Sulphate (SO4), ≤%	-	0.5
Carbonate	-	Test passed
Barium	-	Test passed