Irritation Test / Skin Irritation and Corrosion Toxicity

Describes the In Vitro Reconstructed Human Epidermis Test Method procedures required for hazard identification of irritating chemicals, in accordance with the UN Globally Harmonized System of Classification and Labeling (GHS) Category 2. Reconstructed Human Epidermis Test Method; It is carried out in an environment that closely mimics the biochemical and physiological properties of the upper parts of the human skin.

Irritant test substances can damage the skin as they reduce cell viability below defined threshold levels. Chemical-induced skin irritation, manifested by skin erythema and edema, occurs when chemicals penetrate through the stratum corneum, where they can damage the underlying layers of keratinocytes and other skin cells.

The chemical to be tested is applied to a three-dimensional RhE model consisting of cultured, untransformed human-derived epidermal keratinocytes to create a multilayered, highly differentiated model of the human epidermis. RhE-based test methods are evaluated considering cell/tissue damage and cell viability.

OECD 439: In Vitro Skin Irritation: Classified according to the results of the Reconstructed Human Epidermis Test Method as follows:

Irritant (I), if average tissue viability is <50%, (R38 or GHS Category 2)
If average tissue viability is >50% Non-irritating (NI)

OECD 439: In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method