International GLP: a critical reflection on the harmonized global GLP standard from a test facility viewpoint.

The implementation of the Organisation for Economic Co-operation and Development (OEC D) principles of good laboratory practice (GLP) on an international level is well advanced. However, the OEC D GLP guidelines as well as the corresponding national GLP regulations leave room for interpretation. As a consequence, working in parallel in GLP environments in several countries represents a challenge. Some experiences highlighting key issues are presented in order to create awareness of the international impact of national differences.