The existing EU chemical legislation only covers some of the effects caused by endocrine disruption. In the proposal for the new REACH system, endocrine disrupters are covered by the authorisation procedure based on a case-by-case assessment, but no indication of criteria for the assessment is given. Several toxicological and ecotoxicological screening tests for predicting endocrine disrupting properties of a chemical are now under development and international validation within the OECD, but it will probably take several years before the full range of validated testing methods and criteria are developed. In the meantime there is a need for guidance on how to interpret test results from existing test methods and how to identify a substance as an endocrine disrupter. Regulatory instruments that can be used towards endocrine disrupters should also be considered in this interim period. The aim of this project has been to investigate if and how the OECD Conceptual Framework for Testing and Assessment of Endocrine Disrupters can be used as a basis for regulatory initiatives towards endocrine disrupters. The report includes an assessment of the tests in the OECD Conceptual Framework, including specification of the endpoint for the test and reliability and relevance for effects in humans. This report is expected to serve as a basis for the Nordic contribution to the discussions in EU on interpretation and use of test results indicating endocrine disruption for regulatory purposes and furthermore, how to integrate endocrine disrupters in the new EU chemicals regulation.