... ,Appearance : white or light yellow crystalline powder4,Main content :96.5%min 5,Competitive price, Pass ISO 6,Annuual production:20,000mt Quality ... standard : GB1893-1998Item Company standardAssay ( as Na2S2O5 ) % ≥96.5Fe % ≤0. ... . Kerry Xiao(0086-13762006068) in Yueyang Sanxiang Chemical Co.,Ltd. 96.5% minSodium metabisulfite