National Toxicology Program

Overview and Test Method Evaluation

EpiDerm™ (EPI-200) and EPISKIN™ are three-dimensional reconstructed human skin models that use cell viability as a measure of corrosivity following topical exposure of a test substance. In the TER Assay, corrosive materials are identified by the ability to produce a loss of normal stratum corneum integrity and barrier function in intact rat skin, which is based on a reduction of transcutaneous electrical resistance below a predetermined threshold level.

The European Centre for the Evaluation of Alternative Methods (ECVAM) conducted validation studies of the suitability of these three in vitro methods for identification of substances with the potential to cause human skin corrosion. ECVAM concluded that these methods were able to distinguish between corrosive and non-corrosive chemicals for all of the chemical classes considered. In 2000, subsequent to the ECVAM recommendation, the European Union accepted these methods for corrosivity testing.

In 2001, ICCVAM conducted an evaluation of the ECVAM studies and all other available data on these assays, and recommended that they may be used for assessing the dermal corrosion potential of chemicals in a weight-of-evidence approach in an integrated testing scheme. In this approach, positive in vitro corrosivity responses do not generally require further testing and can be used for classification and labeling.

Test Method Evaluation Report

Background Review Document

OECD Guidelines for the Testing of Chemicals

In vitro human skin model test methods such as EPISKIN™ and EpiDerm™ are accepted internationally via OECD Test Guideline 431 [PDF].

The rat TER test method is accepted internationally via OECD Test Guideline 430 [PDF].