Gene toxicity studies on titanium dioxide and zinc oxide nanomaterials used for UV-protection in cosmetic formulations

Abstract

Titanium dioxide and zinc oxide nanomaterials, used as UV protecting agents in sunscreens, were investigated for their potential genotoxicity in in vitro and in vivo test systems. Since standard OECD test methods are designed for soluble materials and genotoxicity testing for nanomaterials is still under revision, a battery of standard tests was used, covering different endpoints. Additionally, a procedure to disperse the nanomaterials in the test media and careful characterization of the dispersed test item was added to the testing methods. No genotoxicity was observed in vitro (Ames' Salmonella gene mutation test and V79 micronucleus chromosome mutation test) or in vivo (mouse bone marrow micronucleus test and Comet DNA damage assay in lung cells from rats exposed by inhalation). These results add to the still limited data base on genotoxicity test results with nanomaterials and provide congruent results of a battery of standard OECD test methods applied to nanomaterials.

Keywords::

• Cosmetics
• genotoxicity
• test methods
• titanium dioxide
• zinc oxide

Acknowledgements

The authors thank ECNIS (Environmental Cancer, Nutrition and Individual Susceptibility), a network of excellence operating within the European Union 6^th Framework Program, Priority 5: Food Quality and Safety (Contract no. 513943) for support.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper. However, Robert Landsiedel, Lan Ma-Hock, Ben van Ravenzwaay, Stefan Schulte, Markus Schulz, Samantha Champ, Karin Wiench and Wendel Wohlleben are employees of BASF SE, a company marketing nano-scale titanium dioxide and zinc oxide.