Appeal for harmonized scientific criteria for identification and assessment of endocrine disruptors
Endocrine active substances denote substances that can influence the hormonal system of organisms. If this interaction leads to adverse effects, for example health impairments, such substances are called endocrine disruptors. In the European Union, specific regulations have now been passed on endocrine disruptors in different legal areas. However, the scientific basis on which such substances are to be identified and characterized has not been defined yet. For this reason, the European Commission has been asked by the European legislator to present concrete and transparent criteria for the determination of endocrine-disrupting properties of substances. At present, different approaches are being discussed. "The BfR is of the opinion that in assessing substances with endocrine-disrupting properties, the principle of ‘one substance - one assessment’ should be applied", says Professor Dr. Dr. Andreas Hensel, President of the Federal Institute for Risk Assessment (BfR). "If a substance is used in different areas of legislation, any assessment must nevertheless be identical and must be conducted only on the basis of the intrinsic properties of that substance." Professor Hensel adds that a situation where different toxicological limit values are used for the same substance in different areas of legislation such as biocide, pesticide and chemicals law is not acceptable, since the intrinsic toxicity of the substance always remains the same. Already in 2011, the BfR developed, together with the British Chemicals Regulation Directorate (CRD), a structured and tiered assessment concept for endocrine disruptors with regard to human health. This concept was then developed further taking into consideration current scientific discussions on the assessment of endocrine disruptors.
The further developed concept essentially consists of three tiers: in a first step, it is proved whether or not the substance has to be regarded as an endocrine disruptor (Hazard Identification). The basis of this assessment is the internationally accepted definition of the WHO according to which endocrine disruptors constitute exogenous substances, i.e. substances which enter the organism from the outside. These substances change the function of the hormonal system, thereby causing adverse effects in an intact organism. From this definition arise three basic conditions which must be met: on the one hand, it must be certain that the substance impairs relevant functions of the endocrine system. On the other hand, harmful effects must occur as a result of this impairment, and these harmful effects must be present in an intact organism.
For the purpose of identification, all toxicological studies and other scientific information available for a given substance should be considered. All substances which fulfil the above mentioned criteria will be regarded as endocrine disruptors.
For the regulatory decision, however, a differentiation of the substances based on their intrinsic hazardous properties must be made as part of the procedure. Thus, in the second stage of the concept, the hazard potential for humans has to be characterized (Hazard Characterization). For experimental data it is assumed - provided that no information to the contrary exists - that the effects observed in an intact organism or test animal are relevant for humans as well. In addition, a range of additional factors are taken into account, which are applied in internationally harmonised regulations or scientific guidelines for the assessment of toxic effects. The most important factors notably include the specificity, severity, reversibility and consistency of the observed effects. In addition, the potency, i.e. the dose at which these effects occur, is considered to be relevant.
In the third stage of the concept, the specific regulatory decision is taken. By the characterization of the hazard potential this concept makes it possible to identify endocrine disruptors that pose a high level of concern regarding human health. On this basis, the specific regulatory decisions can be taken for the relevant procedure. This can, for example, be a non-approval of such substances as an active ingredient in pesticides and biocides or mandatory authorization of chemicals. The aim of any regulatory decision is to guarantee a high level of protection for humans.
The concept further developed by the BfR goes beyond the proposal presented recently by the European Commission and has the decisive advantage that the characterization of the hazard potential by means of a complex decision matrix (specificity, severity, reversibility, consistency, potency) leads to a scientifically precise, transparent and comprehensible assessment. It can be applied to the relevant substance-based regulation areas and enables consistent implementation of the “one substance - one assessment” principle. In its recently published opinion on this subject, the European Food Safety Agency (EFSA) supports the concept suggested by the BfR.
About the BfR
The Federal Institute for Risk Assessment (BfR) is a scientific institution within the portfolio of the Federal Ministry of Food, Agriculture and Consumer Protection (BMELV). It advises the Federal Government and Federal Laender on questions of food, chemical and product safety. The BfR conducts its own research on topics that are closely linked to its assessment tasks.