Historically, studies using laboratory animals such as the in vivo bone marrow MN assay and the in vivo unscheduled DNA synthesis (UDS) assay were used to further evaluate the genotoxic potential of chemicals that are positive in in vitro genotoxicity assays.According to the 7th Amendment to the Cosmetics Directive of the European Union, since March of 2009, in vivo assays are no longer permitted for genotoxicity testing of cosmetics ingredients.Without in vivo genotoxicity assays, industry and regulators will have to rely solely on the results of in vitro genotoxicity tests.However, while showing high sensitivity for detecting carcinogens, these tests have been shown to produce unacceptably high rate of positive results that are not confirmed in in vivo genotoxicity and/or rodent carcinogenicity tests, i.e."false" positive results.Thus, relying only on results from in vitro genotoxicity assays would severely impact the ability to market potentially safe and beneficial new cosmetic products.To address this issue, we developed micronucleus / Comet assays that are based on reconstructed human skin models.These assays are currently part of a validation exercise sponsored by Cosmetics Europe (formerly COLIPA).This effort is also supported by the European Center for Validation of Altemative Methods (ECVAM).Importantly, in April 2014 (SCCS/1532/14), the European Unions Scientific Committee for Consumer safety (SCCS) highlighted the possibility of in-vitro-only follow-up in case unfavorable results are observed in the standard genotoxicity test battery and emphasizes the utility of 3D skin based genotoxicity assays for such follow-up testing.