Ecotoxicology is a discipline resulting from pollution events that harmed human and environmental health by the mid-twentieth century. Environmental considerations were simply inexistent at this time, and inevitably deleterious effects and environmental disasters followed. These historical events, like Clear Lake disaster in California, will be recalled, as well as new concepts developed, and scientists involved in these findings. A special tribute is given to Professor Jean-Michel Jouany who conceptualized newly acquired knowledge into an emerging discipline, which he named "ecotoxicology" in the 1960s, and understood to be "toxicology in an ecological perspective." However, René Truhaut is considered as the "father of ecotoxicology" by posterity, while his young mentor Jouany was shadowed by the latter. It is timely to "open the book" as concerns these two exceptional personalities and their working relationships, first to set the record straight and second to give credit where credit is due.
Keywords: Chronic toxicity; Clear Lake; Ecosystem; Jean-Michel Jouany; Minamata; René Truhaut.