... dioxide Pacgage 15kg,20kg,25kg,50kg,100kg,200kg iron drums with double polyethylene liners;500kg,1200kg,1800kg intermediate ... :.Food Grade90%Grade88%Grade85%GradeNa2S2O490%88%85%85%Iron(Fe)20ppm20ppm20ppm20ppmzinc(Zn)1ppm1ppm1ppm1ppmsolution appearance clear clear clearclearEDTA/// ... must be always handled and stored in sealed clean iron drums or bulk containers.Avoid contacts with moisture , acids, ...