Strict compliance with the European Pharmacopeia (EP) monographs is not required for closure liners that may be used for pharmaceuticals in the European Union (EU). However, an application for a marketing authorization for a new medicinal product should reference any relevant EP monographs for immediate packaging materials. With respect to immediate packaging materials used in closures of finished medicinal products, the Medicinal Products Directive 2001/83/EC indicates, inter alia, that the identity of the packaging material and its specifications should be provided.