Who Must Explain the Risk? Giving Reasons in EU Chemicals Regulation

EU chemicals regulation offers no single route from scientific dossier to market decision. Under REACH, the Biocidal Products Regulation and the Plant Protection Products Regulation, assessment and final judgment are divided among national authorities, ECHA, EFSA and the Commission, while the grounds may be dispersed among reports, opinions, acts and review decisions. This article places that arrangement within the law of reason-giving and asks what an authority must explain when scientific findings become an information request, approval, restriction, authorisation or refusal. Legislation, case law and selected decision packages show that intelligibility and judicial review require a more specific account where evidence is contested, experts disagree or mitigation supports a favourable decision. The record should identify the decisive findings and uncertainties, explain their bearing on the legal threshold and selected measure, and disclose which body assumed responsibility. Proper reasons can therefore preserve the authority of scientific expertise while keeping regulatory power attributable and contestable.