... as BV, 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, used ... , printing and dyeing, synthetic fiber, leather and other industries. CERTIFICATE OF ANALYSIS ITEMSSTANDARDRESULTSNa2So4 %≥99.00%99.21%FE%≤0.002%0.002 ...