Dermal exposure to chemicals - evaluation of skin barrier damage

Dermal exposure to xenobiotic compounds occurs on a daily basis in many humans, in intended as well as unintended ways. Serious skin problems are caused by household chemical products, mainly by strong anionic surfactants. The purpose of this study was to assess the suitability of two in vitro methods for evaluation of sodium lauryl sulphate (SLS) potential on skin barrier damage. Transdermal electrical conductivity (TEC) according to our design, and the method of in vitro skin permeability of indigotine as a chemical skin integrity marker were used. The TEC values across the skin membrane damaged with 5, 10 and 15 % aqueous SLS solutions for 1 h were 3.92, 5.79, and 7.29-fold higher respectively than the data of TEC across the intact skin membrane. The amounts of indigotine after 20 h permeation through the skin membrane damaged with 5, 10 and 15 % SLS were 2.48, 4.04, and 5.81-fold higher respectively than the measured amount of indigotine permeated through the intact skin. We consider that the measurement of TEC, especially, in combination with a suitable chemical marker can be simple, quick, safe and cost effective in vitro method for prediction the skin barrier damage not only by surfactants, but also for hazard and risk evaluation of other chemical compounds the human skin is exposed to.