L'OREAL has been using alternative methods for almost 30 years and this has led to their current widespread in-house use for evaluation of local effects in safety and efficacy. Alternative methods are used daily to assess eye and skin tolerance, phototoxicity, photoprotection, skin sensitization, percutaneous absorption and skin and hair care. For eye irritation, many years of in-house studies have enabled us to develop and to select the most reliable tests. New in vitro methods have also been developed to help to understand the ocular irritation mechanisms which underlie the irritative properties of new chemicals. In the field of skin irritation, L'OREAL's work has focused mainly on the wide possibilities offered by reconstructed human skins to evaluate the skin tolerance of cosmetics. Today we have managed to introduce Langerhans cells in reconstructed epidermis to develop an alternative to skin sensitization. Besides these in-house investigations either in research or in evaluation, our laboratories have contributed actively to multicentric studies to help the prevalidation/validation process in various fields. The alternative approach is now totally integrated into the safety evaluation strategy, and this allowed L'OREAL to totally ban animal testing on cosmetic products several years ago. In vitro alternatives are very powerful tools: they allow the study of fine mechanisms and the use of human cells. This overall 'in vitro' approach is a scientific, ethical and industrial breakthrough.