When reports surfaced last month that nearly two dozen scientists had gathered in Berlin to reach an “expert consensus” on how to identify endocrine disrupting chemicals (EDCs), it wasn’t immediately clear who attended, how they were selected, or how – or even if – the European Commission would use some of the outcomes to help steer its efforts toward developing criteria for defining EDCs.
As it turns out, the final consensus statement published on May 4 by the Germany-based Federal Institute for Risk Assessment (BfR) reinforces several key principles that would underpin a risk-based approach to regulating EDCs, such as those used in the U.S., Canada and Japan. (You can find more information on the BfR consensus paper on EDCs here.)
That such a diverse group of experts could come together to recognize the validity of risk-based scientific principles speaks volumes about the value it brings to protecting human health and the environment from potential exposure to EDCs.
5 ways risk-based science won the day
- The BfR statement accepts that, to be an “endocrine disrupting” chemical, an adverse health effect must occur. According to the WHO, an endocrine disrupting chemical must alter the function of the endocrine system (i.e., it is endocrine active) AND consequently cause an adverse health affect. If there are no adverse health effects, by definition, a substance is not an endocrine disrupting chemical. The BfR statement adopts the WHO definition.
- The statement reinforces an important distinction between endocrine activity and endocrine disruption. Attempts to characterize endocrine disruptors as any substance that merely interacts with the endocrine system – with no consideration for whether the effect is beneficial, neutral or adverse – have sorely misrepresented the science. The BfR statement makes this point clear: endocrine activity on its own should not trigger a chemical’s identification as an EDC.
- The statement acknowledges the lack of scientific consensus on non-monotonic dose-response relationships and low dose effects. The scientists concluded that consensus was unlikely to be achieved anytime soon, and that consensus was not required to establish criteria for the identification of EDCs. Likewise, in the U.S., that means existing regulatory testing methods like those used by the EPA’s Endocrine Disruptor Screening Program (EDSP) should continue to move forward and be used to screen and test for endocrine disruption.
- The statement’s authors acknowledge that current EU legislation has not been updated to include all relevant and validated tests for endocrine disruption. This statement is a welcome invitation for the EU to now incorporate the validated screens and tests currently used in the EDSP and to apply the results already obtained from the application of the EDSP in the EU weight-of-the-evidence classification of EDCs. The new high throughput assays pioneered in the EDSP, which are insufficient for classification, can be used along with exposure information for prioritization and integrated with toxicity results for weight of evidence determinations.
- The statement acknowledges the importance of taking a weight-of-the-evidence (WoE) approach. WoE approaches consider all available relevant and reliable evidence and take into account the strengths and weaknesses of the underlying study methods and quality. WoE means that mode of action must be considered as well as adverse effects.
BfR and potency – a potential sixth principle?
By the look of some initial comments made in the press, a few European-based NGOs are now scrambling to draw attention away from the risk-based principles the statement endorses. How? By focusing the media’s attention on the only potential area where they believe risk-based principles for regulating EDCs can’t win under the current EU law – and that’s with potency.
First, a quick primer: potency in chemical risk assessment refers to the amount of a substance required to produce a given effect. A chemical that can produce a biological effect at low doses is said to be more potent than one which produces effects only at higher doses.
In the EU, some have considered potency to be optional for inclusion in the first step in chemical risk assessment, hazard identification. Instead, according to the BfR statement, potency becomes relevant in the second step of risk assessment – hazard characterization. Either way, of course, potency is important.
The problem here isn’t with the statement, but with the fact that, under the current EU law, if a pesticide or biocide is identified as an EDC (a hazard) – step one – no further steps in a risk assessment are taken. It doesn’t even make it to step two, or three or four or five. So, even though potency does matter, there’s no consideration of potency, or real-world exposure scenarios, or probability of real-world effects.
According to the logic driving this “hazard-only” approach to regulation, water and much of the natural food we eat would be banned. Does that sound like sensible regulation to you? Of course not.
The BfR scientists didn’t seem to think so either. Instead, they get it – the risk-based approach is the most comprehensive, practical and protective approach to protecting human health and the environment to date.
And the fact that they effectively called out the EU on their “hazard-only approach” only reiterates the concerns the U.S. and other countries have expressed to the Commission about their potential next steps.