... be used in low pressure boiler water system, circulating water system, industrial and municipal cleaning water system and swimming pool.The solid ... HEDP•Na4 is white powder, soluble in water, easily deliquescence, suitable for use in winter and freezing ... contact with eye and skin, once contacted, flush with water. Diphosphonic acid, (1-hydroxyethylidene)-,tetrasodium salt (HEDPNa4)