Used as an analytical reagent in the determination of calcium and magnesium in water samples, phosphonoacetic acid serves as a complexing agent due to its strong chelating properties. It finds application in water treatment processes to inhibit scale formation by binding metal ions that contribute to hardness. Its structure allows effective stabilization of metal ions in solution, making it useful in industrial cleaning formulations and detergents. Additionally, it has been studied for its potential in modifying enzyme activity, particularly as an inhibitor of pyrophosphate-dependent enzymes, which may have implications in antiviral research. Its ability to mimic pyrophosphate enables interference with viral DNA polymerases, showing promise in biochemical and pharmaceutical studies.