How credible is REACH regulation without transparency, quality criteria, assurance, and control?

<ns3:p>Background The European Chemicals Agency (ECHA) has been established to act as an independent body in the context of the implementation of the Regulation on the registration, evaluation, authorisation and restriction of chemicals (REACH) (Regulation (EC) 1907/2006). Quantitative exposure estimates are required for all exposure scenarios where hazardous emissions occur using exposure measurements or exposure models. REACH regulation specifies that exposure models need to be <ns3:italic>appropriate</ns3:italic> and <ns3:italic>quantitative</ns3:italic>. Here, we evaluated the criteria for regulatory exposure models by ECHA. Methods The evaluation was performed by asking ECHA the criteria for exposure models. Results ECHA does not specify any quality criteria for regulatory exposure models or have transparency requirements. Without quality criteria and transparency, there cannot be quality assurance or control. Thus, an <ns3:italic>appropriate</ns3:italic> model cannot be defined. ECHA does not recognize the <ns3:italic>quantitative</ns3:italic> term even though the fundamental requirement for quantitative exposure assessment is quantitative uncertainty assessment. Conclusions As a result of these shortcomings, ECHA R.14 Guidance for occupational exposure assessment allows the use of non-physical models containing qualitative parameters based on non-accessible calibration databases and statistical evaluations. Because of the lack of transparency, non-physical model construct, and subjective input parameters, model results cannot be associated with real-world operational conditions, and quantitative uncertainty assessment is not feasible. This makes the models qualitative by definition and is not applicable to regulatory exposure modelling. This raises questions about whether ECHA has followed its regulatory mandates in implementing the REACH legislation.</ns3:p>