Improving uncertainty analysis in european union risk assessment of chemicals

Abstract

Handling uncertainty in curren European Union (EU) risk assessment of new and existing substances is problematic for several reasons. The known or quantifiable sources of uncertainty are mainly considered. Uncertainty is insufficiently, explicitly communicated to risk managers and decision makers but hidden and concealed in risk quotient numbers that appear to be certain and, therefore, create a false sense of certainty and protectiveness. The new EU chemical policy legislation, REACH, is an opportunity to learn from interdisciplinary thinking in order to evolve to smart risk assessment: an assessment in which awareness and openness to uncertainty is used to produce better characterizations and evaluations of risks. In a smart risk assessment context, quantifying uncertainty is not an aim but just a productive means to refine the assessment or to find alternative solutions for the problem at stake. Guidance and examples are given on how to differentiate, assess, and use uncertainty.

The Integrated Use of Models for the Properties and Effects of Chemicals by means of a Structured Workflow

“…Alternatively, when the dataset is adequate, a more scientifically based approach relies on the use of a sensitivity distribution to derive the thresholds of no concern. A description of these two approaches is given in Verdonck et al [32]. The application of Step 3 (SARs) helps to identify which hazards are likely to be present or absent.…”

A systematic review of methods of uncertainty analysis and their applications in the assessment of chemical exposures, effects, and risks

“…Among them, several used Walker et al (2003)'s definition: "any departure from the unachievable ideal of complete determinism" (Ramsey 2008;Ruggeri 2009). These authors distinguished among characteristics of uncertainty, such as location, nature, and level (Walker et al 2003;Verdonck et al 2007;Ruggeri 2009) or location, nature, International Journal of Environmental Health Research 7 range, recognized ignorance, methodological unreliability, and value diversity among analysts (Knol et al 2009). In contrast, other authors referenced sources of uncertainty definitions that pertain more specifically to the field of chemical risks, and sometimes to an even more specific issue.…”

Conventional Risk Assessment of Environmental Contaminants

“…It is clear that modeling PECs and PNECs includes a vast amount of simplifications and uncertainties, and strategies have been proposed to improve uncertainty analysis in risk assessment of chemicals (Verdonck et al, 2007). Very simplistically, if the PEC/PNEC ratio is greater than 1, the substance is of concern.…”