Sascha Pawlowski

Coral reefs are declining worldwide due to various global and regional factors, with climate change and the associated warming of the oceans being one of the primary drivers. Recreational beach activities lead to the direct emission of sunscreen products and their UV filters into coastal marine environments and thus may impact coral health. However, although sunscreen formulations may be optimized in some regions by using non-hazardous UV filters, in many countries with coral reef abundance, additional emissions may occur due to untreated and insufficiently treated wastewater. For lipophilic ultraviolet absorbing (UV) filters, however, adequate treatment of domestic wastewater would significantly (up to > 90%) reduce such indirect emissions. Furthermore, such measures would also help to improve both river and coastal water quality, as domestic wastewater typically contains many more substances resulting from other uses such as personal and homecare, pharmaceuticals, disinfectants, and biocides. As these provisions are both cost and time consuming, prioritization of improvement needs may be supported by standardized and validated test methods (preferably under ISO) that allow for a toxicity assessment of effluent streams on corals. Furthermore, these methods may also be used to identify substances considered critical for coral health. The ban of certain cosmetic UV filters in some regions may not be considered a suitable solution to maintain coral reefs. Thus, from a more holistic approach, improving wastewater management would contribute to the maintenance of coral reefs on a local scale, especially in areas (e.g., islands originating from volcanic activities) that are less affected by rising sea surface water temperatures.

Coral reefs are globally declining due to various anthropogenic stressors. Amongst those, chemical pollutants, such as pesticides from agricultural runoff, sewage or an overabundance of personal care products in coastal waters due to intense tourism, may be considered as a local stressor for reef-building corals. The extent to which such chemicals exhibit toxic effects towards corals at environmentally relevant concentrations is currently controversially discussed and existing studies are often based on varying and sometimes deficient test methods. To address this uncertainty, we adapted available methods into a reliable and comprehensive acute coral toxicity test method for the reef-building coral Montipora digitata. The toxicities of the four substances benzophenone-3 (BP-3), Diuron (DCMU), copper (Cu²⁺ as CuCl₂, positive control) and dimethylformamide (DMF, solvent) were assessed in a 96 h semi-static test design. Endpoints such as maximum quantum yield, bleaching, tissue loss and mortality were evaluated with respect to their suitability for regulatory purposes. Overall, the endpoints bleaching and mortality yielded sensitive and robust results for the four tested substances. As the test method follows the principles of internationally standardized testing methods (ISO, OECD), it can be considered suitable for further validation and standardization. Once validated, a standardized test method will help to obtain reproducible toxicity results useful for marine hazard and risk assessment and regulatory decision making.

Objective: The aim of this work was to review the principals of environmental hazard and risk assessment (ERA) of cosmetic UV filters registered under EU REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals). Furthermore, effects as obtained from non‐standardized testing methods and organisms from scientific literature were compared against the predicted no effect concentrations (PNECs) as derived based on standardized test methods for the various environmental compartments under REACH.Methods: The REACH dossiers at the ECHA webpage were screened for available information related to basic physico–chemical data (i.e. water solubility, octanol–water partitioning coefficient), PNECs and associated data (data basis, assessment factors (AFs)). Scientific literature was screened for available ecotoxicity data and the adverse effect levels were compared against the derived PNECs under REACH. Current approaches for environmental risk assessments of UV filters were evaluated for its applicability for a direct release scenario.Results: Under REACH, PNECs were derived for all hazardous UV filters. Although, PNECs were often derived for various environmental compartments (i.e. freshwater, marine water, sediment, soil), results from literature focused on aquatic data. Effects as observed within scientific literature matches in principle with the hazardous profile of the UV filters. Effects levels both on the acute and the chronic toxicity as retrieved from the non‐standardized test organisms (literature) were above the derived PNECs under REACH. Currently, ERAs performed for cosmetic UV filters under REACH are solely tonnage driven and thus do not fully capture the use in sunscreens and associated leisure activities.Conclusion: Existing EU REACH regulation is considered as sufficient to evaluate the environmental safety of UV filters used in sunscreens. To cover the direct release of UV filters due to various leisure activities into the aquatic freshwater and marine environment, an additional application‐based ERA is considered necessary.

Organic solvents are often used in aquatic toxicity tests to facilitate the testing of hydrophobic or poorly water-soluble substances such as ultraviolet (UV) filters, pesticides, or polycyclic aromatic hydrocarbons (PAHs). Knowledge of intrinsic effects (i.e., measured as standardized and non-standardized endpoints) of such carrier solvents in non-standardized organisms (i.e., corals), is critical to regulatory processes. Therefore, we exposed the reef-building coral Montipora digitata to the most commonly used carrier solvents ethanol, methanol, dimethyl sulfoxide, and dimethylformamide in the range of 10–100 µL L⁻¹ for 16 days. The effects on mortality, photobiological, morphological, and oxidative stress markers were evaluated. In our study, all solvents resulted in significant morphological and/or oxidative stress responses, but not in mortality. Moreover, ethanol led to a rapid increase in turbidity, thus questioning its suitability as a carrier solvent in aquatic studies in general. Based on our observations, we could rank the solvent effects as follows: dimethylformamide < dimethyl sulfoxide ≈ methanol ≤ ethanol, with dimethylformamide showing the least and ethanol the most pronounced effects. We conclude that the use of solvents in toxicity studies with corals, particularly by examining non-standardized (e.g., morphological, physiological) endpoints, should be taken with caution and requires further elaboration.

Coral reefs have been declining globally at a historically unprecedented rate. Ultraviolet (UV) filters used in sunscreens may contribute to this decline at local scales, which has already led to bans on various organic UV filters in some regions. However, the underlying studies for these bans demonstrated significant flaws in the experimental design due to a lack of validated and standardized testing methods for corals. This study aimed to investigate options for the development of a standard acute toxicity test for the larval stage of scleractinian corals. Planula larvae of two brooding (Leptastrea purpurea and Tubastraea faulkneri) and two spawning (Acropora digitifera and A. millepora) species were exposed to the organic UV filter benzophenone-3 (BP3) for 48 h under static conditions. We observed interspecific variations in toxicity, with A. digitifera being the most sensitive (LC₅₀ = 0.75 µg L⁻¹) and T. faulkneri the least sensitive (LC₅₀ = 2951.24 µg L⁻¹) species. Inhibition of settlement was found to be a useful endpoint leading to an EC₅₀ of 1.84 µg L⁻¹ in L. purpurea larvae. Although the analytical challenges of measuring lipophilic substances in small volume test setups remain, the here applied test design and selected endpoints are suitable for further validation and subsequent standardization.

Ultraviolet (UV) filters used in sunscreens are among the anthropogenic substances that may enter the marine environment by both indirect (via wastewater) and direct pathways (leisure activities). Owing to the recent global decline in coral population, the impact of those UV filters on the coral health is currently under increased investigation. First results from scientists suggest that some of the filters may be toxic to various coral life stages, but an initial cross comparison with existing data from other freshwater organisms does not indicate that corals are specifically more susceptible to UV filters than other standard species. In fact, the available data leading to this conclusion is still vague and based on toxicity and bioaccumulation tests with corals, which are both still at the research stage. To facilitate a proper hazard assessment, robust experimental procedures for coral ecotoxicological studies are considered mandatory. In other words, additional steps should be taken to standardize and validate such new test systems to generate reliable results, which then can be used in regulatory decision making. Furthermore, to facilitate a more detailed and site-specific environmental risk assessment in the marine area, an application-based exposure scenario must be developed. Until these data and tools become available, environmental hazard and risk assessments may be carried out using existing data from freshwater organisms and existing tonnage-based exposure scenarios as a potential surrogate. Integr Environ Assess Manag 2021;17:926–939. © 2021 SETAC KEY POINTS UV filters are key ingredients in sunscreens, with a similar function but decidedly different in their physicochemical properties and environmental hazard profiles. Environmental risk assessments of UV filters are currently based on toxicity data from standard test organisms (i.e., algae, Daphnia, fish) and tonnage-based exposure scenarios, making it difficult to assess their impacts on corals. Results indicate that this approach could also safeguard corals, although uncertainty exists linked to data quality and scenarios used. Standardized coral toxicity tests and application-based exposure scenarios would certainly help to clarify existing uncertainties.

Objective: Sunscreens play a major role in the EU sun protection strategy in order to prevent humans from UV light‐induced skin damage. In recent years, the demand for high‐quality sunscreen products including aspects of broad range and photostability of the UV protection, showing good spreadability onto human skin and excellent sensorial properties during and after application has increased. Environmental aspects are considered. Sunscreens are complex compositions, with UV filters being the key element in the formulations reaching up to about 30% in content in the final product. Some of these ingredients, however, may be regarded as hazardous for the aquatic environment. Nevertheless, the aquatic ecosystem represents only a single environmental compartment, which may be impacted by UV filters. Therefore, the EcoSun Pass (ESP) tool was developed in order to assess the overall environmental impact of UV filters in combination with its efficacy (Sun Protection Factor, SPF and UVA Protection Factor, UVA‐PF).Methods: For that purpose, at first 24 of the EU‐approved UV filters for sunscreen applications were evaluated for their environmental hazard profiles. Nine example UV filter compositions representing both SPF 30 and 50 were evaluated for ecofriendliness using the ESP tool.Results: The results revealed that two out of four SPF 30 compositions are considered as ecofriendly. Likewise, from the SPF 50 two out of five did meet the criteria for ecofriendliness. Furthermore, the results showed that most ecofriendly example formulations have also the lowest overall UV filter content in the product, based on the use of highly innovative and least hazardous UV filters.Conclusion: These results demonstrate that the tool is applicable to various formulations being present on the market and thus allows for a selection of most ecofriendly and efficient UV filters to be used in sunscreens.

The amphibian metamorphosis assay represents an OECD Level 3 and EDSP Tier 1 ecotoxicity test assessing thyroid activity of chemicals in African clawed frog (Xenopus laevis). To evaluate the effectiveness of snout‐vent length (SVL) normalization of hindlimb length (HLL), correlation between the HLL and SVL or body weight was evaluated in the control groups of 10 individual studies from three laboratories. Two studies required separate analysis of the Nieuwkoop‐Faber (NF) stage ≤60 and >60 animals creating a total of 12 data sets. On study day 7, significant positive correlation between HLL and SVL or body weight was observed in eight and seven of the 10 data sets, respectively (r = 0.608‐0.843 and 0.583‐0.876). On study day 21, significant positive correlation between HLL and SVL or body weight was found in three and four of the 12 data sets, respectively (r = 0.452, 0.480 and 0.553 and r = 0.621, 0.546, 0.564 and 0.378). Significant positive correlation between HLL and SVL was found in three of five studies, including ≤NF stage 60 data (r = 0.564, 0.546 and 0.621). In one of eight studies, including >NF stage 60 data, the positive correlation between HLL and body weight was determined (r = 0.378). Negative or no correlation between HLL and SVL or body weight was found in the other late stage data sets. Therefore, use of SVL‐normalized HLL to assess thyroid‐mediated effects in X. laevis tadpoles is not warranted. HL stage relative to body stage should be considered.