Item	90%	88%	85%	food grade
Na2S2 O4	≥ 90%	≥ 88%	≥ 85%	≥ 85%
(Fe)	≤ 20ppm	≤ 20ppm	≤ 20ppm	≤ 20ppm
(Zn)	≤ 1ppm	≤ 1ppm	≤ 1ppm	≤ 1ppm
Clarity	Clarify	Clarify	Clarify	Clarify
EDTA	-	-	-	Qualified
(As)	-	-	-	≤ 1ppm
Other heavy metals(pb)	-	-	-	≤ 1ppm
HCHO	-	-	-	≤ 0.05%
water insoluble matter	≤ 0.05%	≤ 0.05%	≤ 0.05%	-

Packing: Barrels sealed packaging, polyethylene film bag lined with double-layer 15KG/20KG/25KG/50KG/100KG/200KG

Specification: industry grade HG/T 2074-1991 JIS K 1476-1995
                          food grade GB 2682-1995