... AppearanceWhite floating,crystalline powder Content(As Ca)%34.0-40.034.0-40.0 F,≤%0.00750.0075 As,≤%0.00030.0003 Heavy metal(As Pb ... ),≤%0.0020.0015 Pb,≤%-0.0005 Loos on heating(200),≤%10.0 ... - Loos on ignition(800),≤%-10.0 Clear gradeSlightly turbid ...