The Danish Centre on Endocrine Disruptors (CeHoS) has recently published its findings on the current state-of-the-science relating to the risk assessment of endocrine disruptors (EDs). Although several uncertainties exist when it comes to their assessment, there is an ongoing requirement for their evaluation (e.g. under REACH). In this report, some major uncertainties related to the derivation of tolerable exposure levels are discussed, which include:

  • the existence (or not) of a threshold for ED effects
  • non-monotonic dose responses
  • in standard laboratory tests, the lack of assessment of exposure during sensitive periods
  • the limited sensitivity of current testing methods

CeHoS concluded that the approach used for setting reference values for EDs should not generally be based on whether a threshold exists for these effects, as it is difficult or impossible to determine such a threshold with reasonable certainty. A non-threshold approach was recommended to be the default, leading to the determination of a derived-minimal-effect level for endocrine disruption (DMELED). The DMELED could be calculated either by linear extrapolation (e.g. to 10-5 or 10-6 incidence) from a suitable point of departure (PoD), or by the application of a “large assessment factor” (covering specific uncertainties related to the assessment of EDs) to the PoD.

Danish Centre on Endocrine Disrupters (2019). Report on interpretation of knowledge on endocrine disrupting substances (EDs) – what is the risk? http://cend.dk/files/ED_Risk_report-final-2019.pdf

 

The above items were taken from the April 2019 issue of Toxicology and Regulatory News which is sent automatically to members of bibra.

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