Stainless steel is an alloy which is based on iron. 316L S.S. steel is most common type and it contains around 64% iron. The protective, ultra-thin layer of chromium oxide makes stainless steel corrosion free. This protective thin layer is exposed to different influences in daily life, especially in pharmaceutical industries where chlorides are commonly used. Chloride ions affect stainless steel badly as they react with the layer of chromium oxide. The rest of the layer has iron nickel and iron which turns rust colored and cause corrosion over time. Using highly concentrated acids is the best treatment to remove such iron oxides. The disposal and handling acids is simple yet effective.
Modern procedures like derouging are forgoing use of acidic, caustic or harmful substances. Diruneutra is the patented residue free agent available in the US for derouging the surface and makes disposal and cleaning simpler and it is very cost effective to clean the rouge as compared to acid solutions. This product decomposes and targets the iron oxides and it etches nickel or chromium and it leaves the surface of production system. By keeping the iron content monitored in solution, the process of cleaning is complete when Fe level of the metal reaches stable after a specific period of time.