... , SGS, ISO9001.Usage: Primarily used as the filler of dyes and auxiliaries agents, and as the accelerating agent ... of direct dyes, sulfur dyes and vat dyes. In medicine ... and dyeing, synthetic fiber, leather and other industries. CERTIFICATE OF ANALYSIS ITEMSSTANDARDRESULTSNa2So4 %≥99.00%99.21%FE%≤0.002%0 ... 99%min PH:9-11;SGS ,BV;HS Code :2833110000