... colorless to pale yellow aqueous soluti 2-Phosphonobutane -1,2,4-Tricarboxylic Acid(PBTCA)CAS No. 37971 ... (20°C) g/cm31.27 minpH(1% water solution)1.5~2.0Fe ppm10.0 maxChloride ppm10.0 ... Chemicals. When used alone, the dosage of 5-15mg/L is preferred.Package and Storage:200L ... PHOSPHONOBUTANE TRICARBOXYLIC ACID;2-Phosphonobutane -1,2,4-Tricarboxylic Acid;2-Phosphonobutane-1,2,4-tricarboxylic acid PBTC ...