Phosphonobutane Tricarboxylic Acid, (or PBTC) has low phosphoric content. It has structural features of both phosphoric acid and carboxylic acid groups, which enable its excellent scale and corrosion inhibition properties. Its antiscalant property under high temperature is far better than that of organophosphines. It can improve zinc salt solubility, has good chlorine oxidation tolerance, and good composite synergy. PBTC is used as a corrosion inhibitor in boiler feed water. it also has important applications as a chemical intermediate in insecticides, dry cleaning soaps, gas absorbents, rubber chemicals and plasticizers.