A pilot study to characterize hand-to-mouth transfer efficiency of organophosphate flame retardants identified in infant products

This study aimed to determine levels of flame retardants (FRs) in infant products, and to characterize potential for hand-to-mouth transfer efficiency from these products. Select FR concentrations were found in polyurethane foam (PUF) in ten infant products. We examined dermal loading and hand-to-mouth transfer efficiency by simulating handling of two products by participants (n = 9), one of which was handled with and without a fabric covering. Tris (1-chloro-2-propyl) phosphate (TCIPP) was detected in all infant products. The total TCIPP mass transferred to hands was higher for products without covers; however, the relative transfer efficiency (TE) from hands to saliva was higher after handling the product with the cover. Average TCIPP dermal loading was significantly higher without the cover, indicating that these materials may act as a barrier for FR transfer from the PUF to the skin. Estimated highest average daily TCIPP ingestion in infants and children resulting from hand-to-mouth transfer during normal use was 9390 ng/day (1570 ng/kg bw-day) for the uncovered bath product, assuming 100% TE. This study indicates that further research is needed to understand factors that influence individual variability of dermal loading and transfer efficiency, variability of FR concentrations in PUF, and to elucidate the role of fabric coverings on dermal transfer.