Characterization and Management of Uncertainties in Toxicological Risk Assessment: Examples from the Opinions of the European Food Safety Authority.

Uncertainties can be defined as the gaps of knowledge and/or of data sets and/or of methodologies that can exert an unwanted influence on the outcome of a risk assessment. In principle, uncertainties are unavoidable, and thus, a transparent description and weighing of relevant uncertainties should be a necessary component of risk assessment. Examples are provided of uncertainty analysis in recent opinions of the European Food Safety Authority concerning additives, pesticides, and contaminants. Whereas it is difficult to quantify the impact of each specific uncertainty on the outcome, it should be possible to quantify the combined effect of identified uncertainties; also, a stepwise approach may be envisaged, focusing on those issues where a detailed appraisal of uncertainties is needed. On a more general ground, consideration of uncertainty and its sources meets the general requirement for transparency in scientific assessment.