Permeability of Dimethyl Phthalate Through Human Skin Models – Health Risk Assessment

Dimethyl phthalate (DMP) is used widely in cosmetics and personal care products as a solvent, skin penetrant, moisturizer and softener as well as an anti-cracking agent. Dermal absorption is one of the major exposure routes for lower molecular weight phthalates such as DMP and assessing their dermal permeability is important for evaluating the impact and toxicity of such compounds in humans. The aim of this study was to evaluate DMP permeability through different human skin models (Strat-M® synthetic membrane, in vitro reconstructed human epidermis and human dermatomed skin) using solutions containing various types of surfactants, as a simulation of the types of mixtures occurring in cosmetics and personal care products, in order to ascertain the impact that surfactants can have on skin permeability. The results have shown that human skin is the least permeable of the used skin models, and that surfactants (in particular cationic and non-ionic) lead to a significant increase of DMP permeability through all skin models. The performed risk assessment however shows that, for all tested models, the margin of safety was not exceeded.