Temporal aspects in the testing of chemicals for endocrine disrupting effects (in relation to human health and the environment) : final report

Endocrine disruptors are exogenous substances or mixtures that alter function(s) of the endocrine system and consequently cause adverse health effects in an intact organism, its progeny or (sub) populations. Exposure to endocrine disruptors is of particular concern in phases of critical developmental processes, where the endogenous hormonal systems are particularly vulnerable or sensitive to disturbances during certain developmental life stages (e.g. organogenesis), which may consequently lead to serious and irreversible health effects. The Organisation for Economic Co-operation and Development (OECD) is the responsible body for the development and validation of test guidelines for testing endocrine-disrupting properties. The OECD's "Conceptual Framework for Testing and Assessment of Endocrine Disrupters" (as revised in 2012) lists the OECD Test Guidelines (TGs) and standardised test methods available, under development or proposed that can be used to evaluate chemicals for endocrine disruption. However, there are currently gaps and limitations in the existing OECD TGs that hinder the identification of health effects from endocrine-disrupting chemicals (EDCs) such as insufficient coverage of examining the temporal aspects of EDC exposure and effects in the current TGs. Therefore, in order to identify these gaps and limitations of the existing OECD TGs regarding temporal aspects of chemical exposure and effects, a critical literature review on the existing scientific knowledge on this topic was conducted. Afterwards, a comparative analysis was performed between studies following OECD TGs and those using modified or non-OECD TG protocols, e.g. to identify what temporal aspects of EDC exposure and effects have been observed in the non-OECD TG studies but are not addressed in the TGs. This technical report presents the outcomes of the critical literature review and the comparative analysis.