Serial number 

Index name 

Numerical value 

1

Chromaticity (black) ≤

40.0

2

Phosphoric acid (H₃PO₄) content%≥

105-118

3

Phosphorus pentoxide (P₂O₅) content%≥

76-86

4

Chloride (Cl)%≤

0.0005

5

Iron (Fe)%≤

0.0

6

Arsenic (As)%≤

0.01

7

Heavy metal (Pb)%≤

0.002