Fentem, J., P. Botham, J. Harbell, B. Koch-Bocabeille, R. Roguet, and J. van de Sandt.Prevalidation of In Vitro Tests for Acute Skin Irritation. ATLA 1999. 27: 346.

Considerable effort has been directed toward the development and evaluation of alternative tests for the prediction of acute skin irritation in recent years. Following the successful validation of two alternative tests for skin corrosion (Fentem et al. Toxicology in Vitro 12, 483-524, 1998), the ECVAM Skin Irritation Task Force recognized the urgent need to make progress in validating relevant in vitro tests for skin irritation (Botham et al. ATLA 26, 195-211, 1998). In accordance with the recommendations of the Task Force, a prevalidation study on four tests (EpiDerm, EpiSkin, PrediSkin and the non-perfused pig ear model) is being conducted during 1999 and 2000. The main objective of the validation activities is to identify those in vitro tests capable of discriminating skin irritants (I) from non-irritants (NI), as defined according to EU risk phrases (R38; no label) and the harmonized OECD criteria (Irritant; no label). The prevalidation stage involves three main phases: I, protocol refinement, including an assessment of intralaboratory reproducibility (4 chemical [2 I, 2 NI], n=5); II, protocol transfer, including an assessment of interlaboratory reproducibility (6 chemicals [3 I, 3 NI], n=3); and III, protocol performance, incorporating an evaluation of predictive ability and reproducibility/transferability (20 coded chemicals [10 I, 10 NI], n=3). Each test is being conducted in three laboratories, according to the ECVAM prevalidation scheme. An independent Chemicals Selection Sub-Committee has selected the test chemicals (primarily on the basis of unambiguous rabbit skin irritation data from ECETOC database). The outcome of phases I and II will be presented.