Second Edition, January 2014 - This guideline issued in January 2014 replaces Doc. 18 “Passivation of Stainless Steel” (1998) and includes new sections on pickling and electropolishing of stainless steels. Chemical surface treatments such as pickling, passivation and electropolishing can help to assure the successful functional and corrosion-resistant performance of stainless steels for product contact surfaces in the food and beverage industry. This document explains the general principles of those three processes above: Why they are necessary, when and how they should be applied, how they work and which chemicals are used.