Le principe de précaution en droit de l’Union Européene by Alessandra Donati, Brussels, Bruylant, 2021, 396 pp.

The precautionary principle is a cornerstone of environmental regulation, which has taken full effect at the European level. It is a pillar of European Union (EU) actions in environmental affairs, as described in Article 191(2) and (3) TFEU, and it forms the very fabric of environmental law and governance. In this context, Donati ’ s book is a deep dive into the structure and operationalisation of the precautionary principle in EU law. Her excellent contribution to the field of EU environmental law, especially regarding the relationship between law and science in the design and application of the precautionary principle by EU institutions, is needed and timely. Her analysis is sharp, exhaustive and well-written. In this book review, I explain the arguments that underpin the book, as well as its structure and theoretical framework, before concluding on the merits of the work as a whole. Firstly, Donati specifically dissects the role and use of “ experts ” in the assessment of uncertain risks contained in specific behaviours (Chapters 3 and 4). She strongly argues that the strict separation between decision-makers and scientists that was once thought of as the better model did not survive the test of time. In relation to the mad cow disease crisis in the 1990s, she notes that “ all barriers between science and politics seem to have been blurred ” (p. 143). She then shows the ways in which such barriers have been blurred in a very compelling manner. Indeed, the assumption that science can provide certain and neutral answers causes a range of problems, as it is an incorrect conception of how scientific development actually occurs (p. 150). However, such an erroneous conception then allowed for a lack of regulation of the relationships between experts and policy- and decision-makers and a lack of rules concerning the independence of experts and of their financing. Thisdiscussion is crucial to understanding environmental decision-making, as it is