The contribution of dermal exposure to the internal exposure of bisphenol A in man

New findings on Bisphenol A (BPA) contents in thermal printing papers, and receipts, in g/kg concentrations and on its dermal uptake (up to 60%) prompted us to assess the risk arising from dermal exposure. Using physiologically based toxicokinetic modelling, we simulated concentrations in blood, in liver and kidney, the target organs exhibiting the lowest no observed adverse effect levels (NOAEL). By comparing organ concentrations at the dose level of the NOAEL divided by a safety factor of 100 (liver: 50 μg/kg/day; kidney: 500 μg/kg/day), with concentrations arising from the dermal dose of 0.97 μg/kg/day (worst case assumption by Biedermann et al., 2010) this dermal exposure can be assumed safe.Additionally, based on the model simulations the high blood concentrations, reported earlier in the literature, are highly improbable because the related exposure levels are orders of magnitude higher than the currently estimated aggregate exposure levels.

► Dermal exposure may contribute to a relevant extent to the overall internal BPA-exposure. ► Higher blood concentration result from a dermal dose compared to the identical oral dose. ► Even if this considered, reported blood concentrations are too high with respect to estimated external exposure. ► More data should be made available on the external exposure and absorption of BPA on the dermal route.