O-187 Bioavailability and Toxicokinetics of the Common Preservative 2-Phenoxyethanol Following Dermal Exposure in Humans

Introduction 2-Phenoxyethanol (PhE) is a biocide which is used as a preservative in cosmetics but also in metal-working fluids. Occupational prevention measures mainly target the inhalative exposure route, but dermal exposure is equally important. However, little is known on human toxicokinetics of PhE following dermal exposure. Methods A human-experimental study was conducted with five volunteers that were dermally exposed to 412 ± 14 µg PhE/kg bw in a single dose. Blood and urine samples were collected at regular intervals up to 48 hours post-exposure. All samples were analyzed for PhE and for three PhE metabolites. The study was approved by the local ethics committee of the Friedrich-Alexander-University Erlangen-Nürnberg, Germany (No. 296_19B). Results PhE was quickly absorbed with t(max) in blood of about 1.0 h. The main metabolite in both blood and urine was found to be 2-phenoxyacetic acid (PhAA) with 4OH-PhAA and 4OH-PhE identified as minor metabolites. Recovery in urine after 48 h was 44.2 ± 9.9 % PhE. Excretion half-lives of PhE (metabolites) were in the range of 1.7 – 3.9 h. Discussion PhE showed high bioavailability following dermal exposure and is rapidly resorbed and excreted within 48 h with PhAA as the main metabolite in blood and urine. Although, some inter-individual variances of PhE biotransformation were observed, PhAA could be confirmed as a reliable biomarker of exposure to PhE. Conclusion Dermal exposure to 2-phenoxyethanol results in an immediate systemic uptake of PhE, thus pointing to a potential occupational safety issue. The determination of PhAA in urine allows for a reliable biomonitoring of 2-phenoxyethanol.