Case C-29/20: Judgment of the Court (First Chamber) of 14 October 2021 (request for a preliminary ruling from the Oberlandesgericht Köln — Germany) — Biofa AG v Sikma D. Vertriebs GmbH und Co. KG (Reference for a preliminary ruling — Regulation (UE) No 528/2012 — Article 3(1)(a) and (c) — Definitions of ‘biocidal product’ and ‘active substance’ — Conditions — Mode of action other than mere physical or mechanical action — Article 9(1)(a) — Approval of an active substance — Scope of approval)