The rise of complex decision-making in the European Union: boards of appeal as a mechanism to mitigate challenges of scientific uncertainty

This article explores the use of expertise by the boards of appeal (BoAs) within EU agencies to mitigate challenges of scientific uncertainty that arise from specialized decision-making. BoAs have been established as an internal control mechanism with significant potential to substantively address challenges of scientific uncertainty. They are composed of both legal and technical experts in the field of the agency. This article focuses on two specific agencies: the European Union Agency for the Cooperation of Energy Regulators (ACER) and the European Chemicals Agency (ECHA). Recent judgments from the EU courts have heightened expectations for the intensity of review that BoAs should apply on agency decisions, given their expertise. This article introduces the degrees of known, unknown and unknowable uncertainties as a tool to decide the extent to which the BoAs may substantively assess the technical and scientific considerations by the agency. These degrees illustrate that the more consensus on a topic exists, the more stringent the review by the BoAs can be. Conversely, in the case of more uncertainty, the more appreciation may be granted to the agency, although the BoAs should still use their expertise to draw the boundaries of scientific uncertainty.