... ,4-Tricarboxylic Acid(PBTCA) CAS No. 37971-36-1 Molecular Formula: C7H11O9P Molecular weight: 270.13 Properties:PBTCA has ... (as PO43-)%≤0.2Density (20°C) g/cm3 ≥1.27pH(1% water solution)1.5~2.0Fe mg/L≤10.0Chloride mg/L ... eye and skin, once contacted, flush with water. 2-Phosphonobutane-1,2,4-Tricarboxylic Acid(PBTCA)