EDTA refers to the chelating agent with the formula (HO2CCH2)
Sodium Hexametaphosphate is used as a sequestering agent. It is used in the industry of soap, detergents, water treatment, metal finishing and plating, pulp and paper manufacture, synthesis of polymers, photographic products, textiles, scale removal and agriculture. sodium hexametaphosphate was the sequestrant in the original Calgon product. Phosphates have negative environmental impacts.
sodium tripolyphosphate is a sequestrant
disodium citrate is a sequestrant listed in a current Calgon MSDS
Triethanolamine and Diethanolamine are sequestrants (Fe and Ca).