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Monday, 01. January 1996 /


Project title:


Project leader:

Manfred Liebsch  

Financial support:    
Project background:

Phototoxicity, the negative interaction of a compound with (UV) light, is sometimes observed after applying a substance onto the skin. Hence, all compounds that are applied to the skin (drugs, salves or cosmetic products) need to be tested for this reaction.  

The most common way of testing for phototoxicity in the past was the “skin irritation test”, mainly using rabbits for the experiments. Twenty-four hours prior to testing, the animals’ fur is partly shaved, and the test substance is applied to the skin for up to 4 hours. The experimental animals are then individually restrained in a small tube and irradiated with UV light. The area of concern is then observed for several days or even weeks to see if painful inflammations emerge on the animal's skin. This skin irritation test is initially done on one single animal, but if the animal shows a reaction to the procedure and phototoxicity is suspected, more animals are tested.  

Manfred Liebsch and his group received funding from Animalfree Research in 1996 to support their project to develop a new in vitro test for dermal phototoxicity using a model of reconstituted human epidermis called “EpiDerm”. Unlike the previous “full-skin” models, this approach uses a three-dimensional, differentiated model of the human skin. The test material can be applied topically to the EpiDerm skin in different concentrations and irradiated by a sun simulation light (UVA and visible light). Cytotoxicity is then determined one day after irradiation in an assay for assessing cell metabolic activity.    




Liebsch M. (1997): Entwicklung eines neuen in vitro Tests auf dermale Phototoxizität mit einem Modell menschlicher Epidermis. ALTEX 14: 165-174.       


EpiDerm© is sold commecially by Mattek


The EU-guideline 2003/15/EG from 2003 specifically integrated new directives regulating the use of in vivo models for cosmetics under the terms of reference 76/768/EWG. It forbids the use of animals for the purpose of developing new cosmetics since the year 2004 and for single components in cosmetics since 2007. This huge success in animal welfare could only be achieved because valid in vitro models such as EpiDerm had been developed to replace the painful animal experiments.


In 2017 a book chapter entitled "The EpiDerm™ Phototoxicity Test (EpiDerm™ H3D-PT)" in Alternatives to dermal toxicity testing

(Liebsch, M., and Kandarova, H., 2017, pp 483-503)


Keywords: phototoxicity, Validation, ECVAM, RHE