The term "endocrine disruptor" is now commonly used in general and scientific language. It refers to chemical substances, of human or natural origin, able to cause harmful effects in humans or animals through their hormonal properties. However, the exact definition of an endocrine disruptor remains a subject of ongoing discussion. Hormonal communication systems art, involved in numerous physiological processes. Many chemical substances call interfere with such processes. In addition, endocrine systems are multiple. Thus, the potential health consequences are diverse. To date, with few exceptions, the deleterious consequences of exposure to endocrine disruptors on human health have not been proven. The science of endocrine disruption has particularly broad and Undefined borders. This science is rapidly evolving and is thus subject to a number of uncertainties. However, in strictly scientific terms, it provides all opportunity to improve our knowledge on endocrine systems and their pathologies. In societal terms, it provides an opportunity to question the activities of man and the harmful effects on the health and late of mankind and the environment. (c) 2008 Elsevier Masson SAS. All rights reserved.