On April 29, 2024, the German Environment Agency (UBA) posted an item entitled “ZnO nanoforms – REACH substance evaluation: environmental aspects.” The Federal Office for Chemicals, the Federal Institute for Risk Assessment (BfR), and UBA have been conducting a Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) substance evaluation on the registered nanoforms of zinc oxide since 2017. According to the item, based on the studies submitted by the registrants, UBA has concluded that the tested nanoforms have a comparable aquatic toxicity to other zinc compounds and that the harmonized classification in Annex VI of the Classification, Labeling and Packaging (⁠CLP)⁠ Regulation as acute and chronic aquatic toxicity category 1 also applies to the tested nanoforms. The item states that it cannot be excluded that a nanoparticle-specific effect contributes to the overall toxicity of the tested zinc oxide nanoforms, however. The item notes that “[t]here are also slight differences in toxicity both between the different nanoforms and between the nanoforms and the easily soluble zinc chloride tested as a control.” The studies submitted by the registrants “clearly show that the registered nanoforms differ not only in size and geometry, but also in their surface properties, as well as solubility and dispersion stability over time.”

Under REACH, registrants are responsible for ensuring that the available information is sufficient to assess the risks of all forms covered by the registration. The item notes that “[t]he verification of the fulfilment of this obligation is not part of the substance evaluation, but may be subject to random checks by [the European Chemicals Agency (ECHA)] as part of a dossier evaluation.” According to the item, the substance evaluation of zinc oxide by the German competent authorities focuses on the nanoforms contained in the registration dossier. UBA is solely responsible for the environmental aspects of the substance evaluation of zinc oxide, and the aspects relating to human health are the responsibility of the BfR.

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