Environmental occurrence of octocrylene in marine and freshwater systems: a critical review

The use of octocrylene has come under regulatory scrutiny, with concerns regarding its potential environmental risk. A main challenge in assessing environmental risk relates to uncertainties associated with exposure quantification, specifically with the use and release of octocrylene into marine and freshwater systems. A systematic and critical literature review is conducted in this study, consistent with the Criteria for Reporting and Evaluating Exposure Datasets, with the primary aim to collate measured environmental concentrations of octocrylene in surface water systems. The results of the study consequently include considerations regarding the reliability and usefulness of the available data to quantify and/or represent reasonable approximations of environmentally relevant exposure to octocrylene. Significant procedural and methodological inconsistencies were involved among the available studies regarding surface water and sediment sample collection, processing, and analyses. Therefore, accompanying discussion in this study draws attention to (a) the need for well-defined monitoring studies capable of acquiring concentration data that are representative of environmental systems and (b) the need for either an increase in the number and frequency of samples collected or the adoption of time-weighted passive sampling methods at sites to account for spatial, diurnal, and seasonal variabilities. Nonetheless, the existing data provide some understanding of central tendencies in measured environmental concentrations, which may be useful in ground truthing ongoing regulatory environmental risk assessments. The geometric mean concentrations for octocrylene in surface water at sites associated with recreational activities are similar in freshwater (30 ng/L) and marine (37 ng/L) systems. Similarly, the geometric mean concentrations of octocrylene in sediments influenced by potential sources of octocrylene are relatively consistent for samples collected from estuarine (6.9 ng/g dw) and freshwater riverine (4.3 ng/g dw) systems.