Opinion of Advocate General Saugmandsgaard Øe delivered on 20 May 2021.#Toropet Ltd. v Landkreis Greiz.#Request for a preliminary ruling from the Verwaltungsgericht Gera.#Reference for a preliminary ruling – Public health – Health rules concerning animal by-products not intended for human consumption – Regulation (EC) No 1069/2009 – Article 9(d) and Article 10(a) and (f) – Classification of products – Decomposition, deterioration and presence of foreign bodies in the material – Effect on the initial classification.#Case C-836/19.