An in vitro model for quantifying chemical transfer from fabric to and through skin.

Consumer fabrics may be impregnated or contaminated with chemicals capable of penetrating the skin. Some retail-sourced clothing is known to contain high levels of synthetic chemical additives. Biomonitoring studies have demonstrated that exposure to chemically laden clothing can cause an appreciable rise in urinary metabolite concentrations. Yet the fabric-to-skin-to-blood pathway remains poorly quantified. This study uses an in vitro dermal exposure model to measure the rate at which 7-hydroxycoumarin-a nonvolatile, low molecular weight optical brightening agent-migrates out of fabric and into and through the skin. The mass transfer of radiolabeled 7-hydroxycoumarin was quantified by liquid scintillation counting (LSC). Median (24-h average) flux of 7-hydroxycoumarin into the skin was 23 pg/cm2 /h from fabrics loaded with 0.8 ppm of compound, and 138 pg/cm2 /h from fabrics loaded with 8 ppm of compound. Median flux of 7-hydroxcoumarin into a receptor fluid (blood surrogate) was 9.5 pg/cm2 /h from fabrics loaded with 0.8 ppm of compound, and 11 pg/cm2 /h from fabrics loaded with 8 ppm of compound. Quantification of fabric-to-skin and fabric-to-receptor fluid mass transfer coefficients may help assess whether fabrics-especially everyday clothing-are a source of chronic, low-dose chemical exposure.