This document specifies a test method for the determination of the resistance of vitreous and porcelain enamelled articles to attack by alkaline liquids at temperatures between 25 °C and 95 °C. The apparatus used is a cylindrical vessel in which only one enamelled specimen is tested. During the specified method, an enamelled specimen is exposed to attack by an alkaline liquid under specified conditions of temperature and time. The solution is not stirred during the test. The loss in mass is determined and used to calculate the rate of loss in mass per unit area and, if necessary, the corrosion rate. The International Standard ISO 28706-4:2008 has been prepared by Technical Committee ISO/TC 107 "Metallic and other inorganic coatings" and has been adopted without any modifications as EN ISO 28706-4:2011 by Technical Committee of the European Standardization organization, CEN/TC 262 "Metallic and other inorganic coatings", the secretariat of which is held by BSI (United Kingdom). The responsible German committee is Working Committee NA 062-01-63 AA "Prüfung von Emails und Emaillierungen" ("Testing of vitreous and porcelain enamels") at the Materials Testing Standards Committee (NMP) at DIN.