1-Hydroxyethylidenebis(phosphonic acid) acts as human protein tyrosine phosphatase inhibitor. It is also useful for photographic applications. It finds application to strengthen bone, osteoporosis treatment and to treat Paget's disease of bone. In addition, it is used in corrosion inhibition in circulating cool water systems, oil fields and low-pressure boilers with electric power, the chemical industry, metallurgy and fertilizers. It is also utilized for formulating reverse osmosis and thermal desalination anti-scaling agents. Furthermore, it is used in detergents, water treatment, cosmetics and pharmaceuticals.