a composition and methods for use in oilfield waterflood systems are disclosed . the composition is comprised of a phosphonate , a copolymer , and a permanganate and is effective at inhibiting the corrosion of metallic systems in petroleum oilfields caused by chlorine dioxide . methods of use of phosphonate and permanganate alone are also disclosed . chlorine dioxide is used in oilfield waterflood systems to control sulfides and sulfate reducing bacteria . however , chlorine dioxide is highly corrosive to the metallic components in the processing equipment of an oilfield system . the most effective system currently used to inhibit corrosion caused by chlorine dioxide comprises chromates . however , chromates are highly toxic and their use throughout the country is becoming increasingly restricted . the use of a composition comprised of 1 - hydroxyethylidene diphosphonic acid , a copolymer comprised of acrylic acid / allyl hydroxy propyl sulfonate ether and potassium permanganate has proved to be more effective than chromates as a chlorine dioxide corrosion inhibitor without the serious toxicological effects caused by the use of chromates .