title: Read-across estimates of aquatic toxicity for selected fragrances.
abstract: Read-across as a non-animal testing alternative for the generation of risk assessment data can be useful in those cases where quantitative structure-activity relationship (QSAR) models are not available, or are less well developed. This paper provides read-across case studies for the estimation of the aquatic toxicity of five different fragrance substances, and proposes a pragmatic approach for expressing uncertainty in read-across estimates. The aquatic toxicity estimates and their uncertainties are subsequently used to estimate fresh water compartment Predicted No-Effect Concentrations (PNECs), with their two-sided 90% Confidence Intervals (CIs). These PNECs can be used directly in risk assessment. The results of the musk fragrance read-across cases (musk xylene, musk ketone and galaxolide) are compared to experimentally derived PNEC values. The read-across estimates made by using similarity in a hypothesised mechanism of action for (acute) toxicity of musk xylene gave a PNEC of 2μg/L (90% CI 0.0004-13.5μg/L) with the Species Sensitivity Distribution (SSD) approach. This estimated value is 1.8 times above the experimentally-based fresh water PNEC of 1.1μg/L. For musk ketone and galaxolide, the PNEC values based on the SSD approach and employing a toxicity mechanism-based read-across were 2.0 times greater, and 4.9 times below the experimentally derived PNEC values, respectively.
authors.affiliation: National Institute for Public Health and Environment, Bilthoven, The Netherlands. emiel.rorije@rivm.nl
authors.forename: Emiel
authors.initials: E
authors.lastname: Rorije
authors.forename: Tom
authors.initials: T
authors.lastname: Aldenberg
authors.forename: Willie
authors.initials: W
authors.lastname: Peijnenburg
mesh_terms: D000818:Animals; D001578:Benzopyrans / Q000633:toxicity; D017686:Oncorhynchus mykiss; D010476:Perfume / Q000633:toxicity*; D021281:Quantitative Structure-Activity Relationship; D018570:Risk Assessment; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D014992:Xylenes / Q000633:toxicity
chemical_list: D001578:Benzopyrans; D010476:Perfume; D014874:Water Pollutants, Chemical; D014992:Xylenes; C033119:galaxolide; C031447:musk xylene; C031448:musk ketone