Lacquers are commonly used in food and beverage can applications to protect the ingredients from interaction with the metals in the packaging. Lacquer integrity testing can be used to ensure package manufacturers as well as food and beverage companies that the packaging will be adequate for the application.
The continuity of internal coatings is measured as a current proportional to the area not covered by the internal coating. In addition, a visual indication that the coating is not continuous is provided by the deposition of copper.
The method is based on BS 2006:1984 Appendix C.