Purity ( counted as CaCO₃)        

≥ 98.0

Acid Insoluble Matter            

≤ 0.20

Heavy Metals               

≤ 0.002

Arsenic                   

≤ 0.0003

Loss on Drying               

≤ 2.0

Water absorption

15-17ml/15g

Iron                      

≤ 0.015

Lead                                 

≤ 0.0003

PH (20% suspension)                                   

9.0-10.0

whiteness        

≥94.0

Residue (325 mesh)      

≤ 0.3

Total Aerobic           

≤100 cfu/g