Issues in the inhalation toxicity testing and hazard assessment for low density particulate materials such as synthetic amorphous silica (SAS)

Wolfgang Dekant*, Evangelia E. Antoniou, Axel Bosch, Gustav Gerd Bruer, Thomas Colnot, Otto Creutzenberg, Claus Peter Drexel, Rodger Duffin, Nils Krueger, Jürgen Nolde, Craig Poland, Dirk Schaudien, Tobias B. Schuster, Michael Stintz, Klaus Weber, Benno Wessely, Maurice P. Zeegers

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Inhalation toxicity testing of particulate materials is mandated for classification. According to CLP, particulate materials should be tested as marketed and many particulate materials are marketed as non-respirable particles. However, OECD TG 413 requires exposure to particle sizes that are respirable and reach the alveoli. The requirement for exposure of rats to respirable particles is thus in contrast to CLP and requires the application of high shear forces. The exposure to artificially small particles causes a number of issues that hamper the interpretation of the results of the testing. These issues are aerosol altering in the exposure system, assessment of the adversity of the inflammatory lung responses, inclusion of recovery groups, and extrapolation of the results to humans exposed under occupational condition. In addition, effects of many particulate materials after testing according to OECD 413 are not intrinsic properties, but a general reaction of the lung to the deposited material, show very similar NOAECs for chemical diverse materials, and often are completely reversible.
Original languageEnglish
Number of pages10
JournalToxicology Letters
DOIs
Publication statusE-pub ahead of print - 1 Jan 2023

Keywords

  • Classification and labelling
  • Inhalation toxicity
  • Lung responses
  • OECD TG 413
  • Particulate materials

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