The substance evaluation of zinc oxide by the German competent authorities focused on the nanoforms contained in the registration dossier. On a publication dated 29.04.2024 UBA concluded that the tested nanoforms have a comparable aquatic toxicity to other zinc compounds and that the harmonised classification in Annex VI of the ⁠CLP⁠ Regulation as acute and chronic aquatic toxicity category 1 also applies to the tested nanoforms. They also highlighted that a particle specific effect cannot be excluded and may contribute to the overall toxicity of the tested zinc oxide nanoforms. They found slight differences in toxicity both between the different nanoforms and between the nanoforms and the easily soluble zinc chloride tested as a control.

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