Skin Surface Film Liquid as New Migration Medium for the Determination of PAHs Released from Rubber Containing Consumer Goods

Abstract

Exposure of consumers, in particular children, to polycyclic aromatic hydrocarbons (PAHs) via contact with consumer products has been the subject of considerable public attention over the last years. Eight PAHs with a harmonized classification as carcinogen 1B, according to the Regulation EC No 1272/2008 on classification, labeling and packaging of substances and mixtures, have been identified in plastic and rubber contained in some consumer articles, such as toys, bicycle grips or sporting goods. These constitute a potential source for dermal, or even oral, exposure. Concerning the former, it is desirable to develop easy and reliable methods for migration determination using simulated environments that mimic as realistically as possible the hydro-lipidic film on human skin composed of aqueous sweat and sebum. This work proposes a protocol for the determination of PAH release from rubber using a migration simulant that mimics real skin conditions. Various compositions of skin surface film liquid (SSFL), a mixture of aqueous sweat and sebum, were tested for their stability and suitability for the measurements. The results indicated that SSFL containing 0.2% sebum showed good agreement with relative migration rates obtained using 20% ethanol, which in past studies has proved to be a valid migration medium for this purpose. The aqueous SSFL has the advantage that it does not interact with the elastomer sample matrix. The SSFL described in this work may serve as a migration simulant for future product-to-skin migration studies, in which the simulant's properties need to realistically reflect the conditions on human skin.