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Legal and practical challenges in classifying nanomaterials according to regulatory definitions


The European Union (EU) has adopted nano-specific provisions for cosmetics, food and biocides, among others, which include binding definitions of the term “nanomaterial”. Here we take an interdisciplinary approach to analyse the respective definitions from a legal and practical perspective. Our assessment reveals that the definitions contain several ill-defined terms such as “insoluble” or “characteristic properties” and/or are missing thresholds. Furthermore, the definitions pose major and so far unsolved analytical challenges that, in practice, make it nearly impossible to classify nanomaterials according to EU regulatory requirements. An important purpose of the regulations, the protection of human health and the environment, may remain unfulfilled and the development of innovative applications of nanomaterials may be facing a path full of (legal) uncertainties. Based on our findings, we provide five recommendations for a more coherent and practical approach towards the regulation of nanomaterials.

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The authors thank M. Velimirovic for discussion on analytical techniques. This work was funded by the Nano-Norms-Nature research platform of the University of Vienna.

Author information

A.P. conceived and supervised the project. M.M. performed the literature search and drafted the manuscript. M.M. and I.E. performed the legal analysis. M.M., T.H., F.v.d.K. and A.P. performed the practical assessment. M.M. and A.P. made the figures. All authors contributed to writing and editing the manuscript.

Competing interests

The authors declare no competing interests.

Correspondence to Thilo Hofmann or Antonia Praetorius.

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Fig. 1: Visualization of types of materials or structures classified as nanomaterials by the Cosmetics, Novel Food and Biocide Regulations according to their individual size specifications.
Fig. 2: Schematic representation of the effects of measurement artefacts on the classification of a material as ‘nano’ or ‘non-nano’.