A tiered approach to the use of alternatives to animal testing for the safety assessment of cosmetics: Skin irritation

Abstract

Evaluation of the skin irritancy and corrosivity potential of an ingredient is a necessity in the safety assessment of cosmetic ingredients. To date, there are two formally validated alternatives to the rabbit Draize test for skin corrosivity in place, namely the rat skin transcutaneous electrical resistance (TER) assay and the Human Skin Model Test using EpiSkin, EpiDerm and SkinEthic reconstructed human epidermal equivalents. For skin irritation, EpiSkin, EpiDerm and SkinEthic are validated as stand-alone test replacements for the rabbit Draize test. Data from these tests are rarely considered in isolation and are evaluated in combination with other factors to establish the overall irritating or corrosive potential of an ingredient. In light of the deadlines established in the Cosmetics Directive for cessation of animal testing for cosmetic ingredients, a COLIPA scientific meeting was held in Brussels on 30th January, 2008 to review the use of alternative approaches and to set up a decision tree approach for their integration into tiered testing strategies for hazard and safety assessment of cosmetic ingredients and their use in products. In conclusion, the safety assessments for skin irritation/corrosion of new chemicals for use in cosmetics can be confidently accomplished using exclusively alternative methods.

Alternative Methods to Animal Testing for the Safety Evaluation of Cosmetic Ingredients: An Overview

“…A decision tree for hazard assessment and labelling, using a weight of evidence (WoE) approach, involves a step-wise evaluation of firstly, physicochemical characteristics, (Q)SAR and existing data, to identify and rule out corrosive chemicals for further testing; secondly, an in vitro corrosivity test; and, finally, an in vitro irritation test to distinguish between irritants and nonirritants. In conclusion, evaluation of the skin irritation potential of new chemicals for use in cosmetics can be confidently accomplished using only alternative methods [20].…”

“…In conclusion, evaluation of the skin irritation potential of new chemicals for use in cosmetics can be confidently accomplished using only alternative methods [20].…”

Applicability of in vitro tests for skin irritation and corrosion to regulatory classification schemes: Substantiating test strategies with data from routine studies

“…2) in accordance with the strategy described by Cosmetics Europe (formerly COLIPA, Macfarlane et al, 2009). In this respect if a material was expected to be corrosive, the in vitro skin corrosion test was performed first.…”

Keratinocyte Culture Techniques in Medical and Scientific Applications

“…Up to now the rabbit Draize test has been used for this purpose, consisting of determination of oedema / erythema after topical application of the test substance. But apart from the animals suffering pain, the prediction of the irritancy potential is not always correct (Macfarlane et al, 2009). As the 3D skin equivalents are physiologically similar to natural skin they present an alternative to animal testing (Mertsching et al, 2008).…”

“…Here, single-cell assays under submerged culture conditions, epidermal equivalents, skin equivalents and excised skin under air-liquid-interface culture conditions serve as different kinds of models with different advantages and drawbacks of each (Gibbs, 2009). Now, several commercially available skin equivalents (EpiDerm®, Episkin® and SkinEthic®) are validated as stand-alone test replacements for standard animal experiments (rabbit Draize test) (Macfarlane et al, 2009). But even fifteen years ago, skin models have already been tested for their use in the prediction of skin irritation and for the study of mechanisms of contact irritant dermatitis (Osborne & Perkins, 1994).…”