Risk assessment from topical exposure to chemical in human requires reliable models and test procedures. For such study, requires numerous replicates due to the variability of the donors. According to their similarities to native human tissue in terms of morphology, lipid composition and biochemical markers, reconstructed human epidermisex vivo human skin is the tool recommended by regulators. However, its use is time consuming and(RhE) have been identified as useful tools for the in vitro testing of phototoxicity, corrosivity and irritancy. These last years, some papers claim that RhE are appropriate alternatives to human skin for the assessment of skinpermeation and penetration in vitro1,2. Such studies were conducted under infinite-dose conditions to measure permeability coefficient.Among all RhE models commercially available, Episkin the tissue in a diffusion cell® from SkinEthic ( are particularly adapted for testing. Indeed, its design allows to measure penetration directly in the insert without mounting3.