A precise definition is important because the majority of the substances that may interact with the endocrine system result in activity that is, or in some cases, even essential to our well-being. Terms becoming popular in media reports mislabel many chemicals as “endocrine disrupting chemicals” or “EDCs,” when, in fact, scientific study is still under way or does not support such labels. From a regulatory policy and scientific perspective, it is important to focus on those substances that have a real potential to cause harm to people or the environment.