Reproductive toxicity, with its many targets and mechanisms, is a complex area of toxicology; thus, the screening and identification of reproductive toxicants is a main scientific challenge for the safety assessment of chemicals, including the European Regulation on Chemicals (REACH). Regulatory agencies recommend the implementation of the 3Rs principle (refinement, reduction, replacement) as well as of intelligent testing strategies, through the development of in vitro methods and the use of mechanistic information in the hazard identification and characterization steps of the risk assessment process. The EU Integrated Project ReProTect (6th Framework Programme) implemented an array of in vitro tests to study different building blocks of the mammalian reproductive cycle: methodological developments and results on male and female germ cells, prostate and placenta are presented.
The identification of reproductive toxicants and their mechanisms of action is a major scientific challenge during safety assessment of chemicals; indeed, reproductive toxicology is one of the most complicated fields of toxicology, due to multiple organs and tissues involved, potentially different modes of toxicant action and dependence on the endocrine system. In particular, endocrine disrupters (EDs) represent a big challenge for experimental toxicology, due to their complex effects on signal networks and programming. Besides the scientific challenge, the assessment of the impact of chemicals on the reproductive cycle is also a major ethical and social issue and needs to be considered since it deals with life stages that are potentially more susceptible and are pivotal for the protection of new generations (see also the new paradigm of "sustainable food safety").