Dansyl chloride labelling of stratum corneum: its rapid extraction from skin can predict skin irritation due to surfactants and cleansing products.

The irritation potential of surfactants and body cleansing products was determined by evaluating the removal of dansyl chloride from the skin. Dilute solutions (2% active ingredient, w/v) of surfactants and soap extract fluorescence from the skin within 30 min. This is probably a physicochemical effect as it is too rapid to be due to a modification of epidermal cell turnover rate. Such an extraction of the fluorescent dye occurs without any clinical sign of irritation. However, it may represent an early phase of the skin irritation process, because it is related to the ranking of irritant products as determined by other assessment methods.