Dermal exposure assessment of polycyclic aromatic hydrocarbons: in vitro percutaneous penetration from lubricating oil

Objectives: Percutaneous penetration of polycyclic aromatic hydrocarbons (P AHs) is affected by various factors connected to exposure conditions. The n ature of the matrix, such as that of oil, can strongly affect their percuta neous penetration. Risk assessment should consider these effects. We examin ed the effect of matrix on percutaneous penetration of PAHs, particularly t hat of lubricating oil. Methods: The test apparatus consisted of an in vitr o static diffusion cell system using full-thickness monkey (Cercopithecus a etiops) skin as the membrane and saline solution with gentamycin sulfate an d 4% bovine serum albumin as receptor fluid. Chemical analysis of PAHs in t he samples obtained from cells was carried out by inverse-phase HPCL, and t he results were read by spectrofluorimetry. Results: Comparing the penetrat ion of 13 PAHs from a lubricating oil and from acetone solution with artifi cial sweat resulted in a significantly slower passage from the oil matrix f or acenaphthene, anthracene, phenanthrene. fluoranthene, naphthalene, pyren e, fluorene (Mann-Whitney U test, P < 0.05). No significant differences in the passage were found for chrysene because, in the test with oil, its conc entration was very often below the detection limit. For benzo[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo[a]pyrene it was poss ible to demonstrate a passage through the skin only when compounds were app lied in acetone solution with artificial sweat. Conclusions: The results of the study suggest the necessity of dermal penetration data relevant for ri sk assessment, obtained under experimental conditions similar to the real e xposure conditions.