Article published on guidance for assessment of endocrine disrupting properties of chemicals

Building on the findings of the 2008 Task Force and 2009 Workshop on identifying endocrine disrupting effects, an article is now being published in Regulatory Toxicology and Pharmacology that presents refined guidance and addresses some key considerations raised by the regulatory, academic and industry scientists who attended the Workshop.


The European legislation on plant protection products (Regulation (EC) No. 1107/2009) and biocides (Directive 98/8/EC), as well as the regulation concerning chemicals (Regulation (EC) No. 1907/2006 “REACH’) only support the marketing and use of chemical products on the basis that they do not induce endocrine disruption in humans or non-target species. However, there is currently no agreed guidance on how to identify and evaluate endocrine activity and disruption. Consequently, an ECETOC Task Force was formed in 2008 to provide scientific criteria that may be used within the context of these three legislative documents.

The report created by the Task Force (Technical Report 106, June 2009) reviews and summarises existing definitions of an endocrine disrupter as well as the test methods currently available to identify endocrine activity and/or toxicity. Specific scientific criteria for the determination of endocrine disrupting properties that integrate information from both regulatory (eco)toxicity studies and mechanistic/screening studies are proposed. These scientific criteria rely upon the nature of the adverse effects detected in regulatory (eco)toxicity study(ies) that give concern for endocrine toxicity and the description/understanding of the mode of action of toxicity which scientifically support and explain the adverse effects. The criteria developed are presented in the form of flow charts for assessing relevant effects for both human and environmental species (see figures 1, 2 and 3 below). These charts are illustrated using example substances. In addition since all chemicals having endocrine disrupting properties may not represent the same hazard, an element or assessment of potency is also proposed to discriminate chemicals of higher concern from those of lower concern.

Figure 1: View larger image at

Figure 2: View larger image at

Figure 3: View larger image at

ECETOC presented this proposal (Technical Report 106¹) at a Workshop of regulatory, academic and industry scientists (Barcelona; June 29-30, 2009) to evaluate the approach as a concept for identifying endocrine disrupting properties within a regulatory context. The outcome of this Workshop has been published in a separate report (Workshop Report 16 and Addendum²).


Bars, R., et al. Science based guidance for the assessment of endocrine disrupting properties of chemicals.

Regul.Toxicol.Pharmacol.(2010), doi:10.1016/j.yrtph.2010.09.003. Link:

ECETOC reports available for free download:

¹ TR 106 : Guidance on Identifying Endocrine Disrupting Effects (June 2009)

² WR 16 and Addendum: Guidance on Interpreting Endocrine Disrupting Effects + Addendum (October 2009)