... GradePhoto GradeAppearanceWhite CrystalAssay, %99.0 MIN99.3 MIN99.5 MINChlorides, %0.2MAX0.2 MAX0.2 MAXSulphates, PPM200 ... MAX100 MAX50 MAXLoss on Drying, %0.5 MAX0.5 MAX0.3 MAXHeavy Metal (as Pb, Hg)PPM5 ... .0 MAXVolatile, %--Qualified0.5 MAXBromates, PPMQualifiedQualified10 MAXIodide, PPM--Qualified50 MAXMinor Elements, PPM--Qualified0.5 MAXPH ValueQualifiedQualified5.5-8.5 Potassium Bromide