ETHYLHEXYL METHOXYCINNAMATE

Sea salt increasingly harbors organic contaminants from personal care products, yet current monitoring methods lack spatial resolution and require destructive sampling. This study introduces an innovative analytical framework integrating Laser-Induced Fluorescence (LIF) Hyperspectral Imaging (HSI) with machine learning for the rapid, non-destructive detection of sunscreen residues on salt crystals. To simulate contamination, seawater from the Mediterranean coast (Alexandria, Egypt) was spiked to achieve a 10 mg/L sunscreen concentration within the seawater matrix prior to crystallization; this formulation contained Ethylhexyl Methoxycinnamate, Homosalate, and Ethylhexyl Salicylate. A SOC710 HS camera (128 bands) acquired fluorescence data under 450 nm laser excitation. Raw data underwent preprocessing and dimensionality reduction via Sparse Principal Component Analysis (Sparse PCA, λ = 0.5, k = 4 components, 73.4% sparsity). A Support Vector Machine (SVM) with an RBF kernel was trained on these sparse features. Performance evaluation employed tenfold stratified cross-validation, an 80-20 holdout test on ROI-based spectra, and independent sample validation against manually annotated pixel-wise ground-truth masks. While ROI-based tests yielded near-perfect accuracy under ideal conditions, full-image evaluation achieved ≈96% pixel-wise accuracy (precision ≈ 0.99, recall ≈ 0.95, F1 ≈ 0.97), providing a realistic estimate under heterogeneous conditions. Full-image classification mapped widespread contamination (57.8% of pixels), whereas an independently prepared clean salt sample produced zero false positives. The integrated Sparse PCA-SVM framework transforms fluorescence-imaging data into spatio-chemical maps, simultaneously revealing contaminant presence and spatial distribution on salt surfaces, thereby offering a powerful paradigm for the interpretable monitoring of organic pollutants in food materials.

Eye discomfort is a common issue for consumers using sunscreen products. While UV filters are suspected of being the main cause, no clear scientific evidence has been found to support this hypothesis. This research aims to develop a scientifically effective eye irritation screening method to provide a scientific explanation for the eye discomfort caused by UV filters. In order to assess the ocular irritation of two UV filters, Octocrylene (OCT) and Ethylhexyl methoxycinnamate (OMC), a combination of in silico and in vitro methods was employed. In silico prediction was conducted using seven computational ADMET prediction models (e.g. AdmetSAR 3.0, ADMETlab 2.0). The i n vitro experimental validation included Bovine Corneal Opacity and Permeability (BCOP) and Short Time Exposure (STE) assays, and TRPV1 ion channel activation was probed using TRPV1-overexpressing rabbit corneal epithelial cells (TRPV1-OE SIRC cells). Different in silico toxicology prediction models did not yield consistent results regarding the eye irritation potential of the two UV filters. The results of the BCOP and STE tests showed that both UV filters were nonirritating. Detection of TRPV1 channel activation indicated that OCT can induce Ca 2+ influx in cells, resulting in ocular discomfort, while OMC did not. These results indicated that this in vitro screening method based on the activation of the TRPV1 channel is more sensitive in detecting stinging sensations in the eyes. This mechanism may provide a possible explanation for UV filter-induced eye discomfort and has potential for screening other cosmetic ingredients that cause such discomfort without irritation.

All around the world, the hairdressing sector constitutes a major occupational group, including about 90% women, most of whom are of reproductive age. Hairdressers are continuously exposed to numerous chemicals used in hair products, including endocrine-disrupting compounds such as resorcinol, parabens, phthalates, and UV filters. Few biomonitoring studies have explored occupational exposure to endocrine disruptors in hairdressers, and no data were found on their impact on the thyroid hormone system. Resorcinol is an oxidative hair dye with thyroid-disrupting properties that decrease thyroid hormone synthesis and could alter neurodevelopmental functions during fetal and perinatal stages in case of maternal exposure. This study aims to assess the occupational exposure to resorcinol in French hairdressers and analyze the relationship with biological thyroid parameters, taking into account the occupational exposure to other potential thyroid disruptors (parabens and UV filters like benzophenone and cinnamates). An exposed-unexposed cross-sectional study is proposed involving female hairdressers aged 18 to 45 years (working in hair salons) compared to occupationally unexposed controls (employed in office activities), who are recruited within 14 French occupational health centers. The hairdressers are followed during a 5-day working week to assess exposure data at both the individual level and the salon level. Urinary samples for the measurement of thyroid disruptors (resorcinol, parabens, metabolites of ethylhexyl methoxycinnamate, and benzophenone-3) are collected at 6 time points (before the day 1 shift, before and after the day 3 and day 4 shifts, and before the day 5 shift). Daily work tasks and use of hair products are self-reported within the workplace, and a complete inventory of hair products within the salon is carried out. Thyroid disruption effects are assessed by measuring blood thyroid parameters: triiodothyronine, thyroxine, thyroid-stimulating hormone, thyroglobulin, thyroperoxidase, and thyroglobulin antibodies. To assess nonoccupational exposure to thyroid disruptors and other confounding factors, information on sociodemographic data, place of residence, food and tobacco consumption, personal use of care products, professional career, and medical history is collected through questionnaires. Regarding statistical analysis, urinary samples from hairdressers and controls will be compared, and adjusted multivariable models will be used to analyze health outcomes. The study duration extends from 2022 to 2027. As of December 2025, 9 occupational health centers have enrolled 66 hairdressers (employed in 54 hair salons) and 30 occupationally unexposed participants. The results will represent the first data on occupational exposure to resorcinol in France and its relationship with thyroid hormones in hairdressers. Following a multidisciplinary approach that includes biomonitoring, epidemiology, and exposure data collection at both the hairdressers and salon levels, this study enables an in-depth assessment of exposure to the thyroid disruptors in the workplace. Together with the inventory of hair products, these results may enhance the tools for chemical risk assessment and prevention in hair salons.

Although the use of ultraviolet (UV) filters in personal care products is steadily increasing, their ecological consequences remain poorly characterized despite evidence of persistence and bioaccumulation in marine systems. In parallel, climate change stressors such as rising temperatures and fluctuations in salinity are known to modulate the toxicity of contaminants and the physiological tolerance of marine organisms. The combined action of these factors can intensify biological stress, highlighting the need for studies that evaluate pollutant effects under realistic multi-stressor scenarios. This study investigated the biochemical effects of octinoxate (also known as ethylhexyl methoxycinnamate, EHMC), a widely used organic UV filter, on the sea urchin Paracentrotus lividus under environmentally relevant conditions. A 28-day laboratory exposure was conducted using three EHMC concentrations (50, 500, and 5000 ng/L) under control conditions (17 °C, salinity 35) and climate change scenarios (21 °C, salinity 40). Multiple biomarkers were analysed, including metabolic activity, antioxidant and biotransformation responses, redox balance, cellular damage, and neurotoxicity. Results showed that the biochemical responses of P. lividus were significantly influenced by environmental conditions. Combined exposure to EHMC and elevated temperature (21 °C) induced marked oxidative stress, metabolic alterations, and shifts in detoxification responses. These effects were less pronounced under increased salinity, though still detectable. The present findings emphasize the heightened vulnerability of marine invertebrates to chemical pollutants under climate stress. Furthermore, the present study highlights the importance of integrating multiple stressors into ecotoxicological assessments and supports the use of bioindicator species, such as P. lividus, for more realistic environmental risk evaluations. Given that UV filters remain understudied contaminants and that data on their effects in echinoderms are still almost nonexistent, this work provides a timely contribution and highlights a critical knowledge gap that warrants urgent scientific attention.

UV filters used in personal care products are increasingly recognised as emerging contaminants due to their persistence and ecological risks. Detected in aquatic systems at concentrations from ng L -1 to μg L -1 , their monitoring is essential for environmental risk assessment but challenging because of their diverse physicochemical properties, requiring sensitive analytical methods. This study optimised a solid-phase extraction gas chromatography-tandem mass spectrometry (SPE-GC-MS/MS) method for the simultaneous determination of twelve UV filters in marine waters. The method showed suitable linearity, precision, and recoveries, with detection limits below 1 ng L -1 . Seawater samples collected along the Adriatic coast (Rimini and Riccione, Italy) during peak recreational activity were analysed. All twelve UV filters were detected, with octocrylene (up to 23,100 ng L -1 ), homosalate (up to 16,400 ng L -1 ), and ethylhexyl salicylate (up to 10,900 ng L -1 ) being most abundant. Trans-2-Ethylhexyl methoxycinnamate (E-EHMC, the trans isomer of octinoxate, 13-1474 ng L -1 ) occurred consistently with its isomer Z-EHMC (cis-octinoxate), contributing 18-64 % of total (E + Z)-EHMC, suggesting in situ photochemical conversion, since the cis form is negligible in cosmetic products. Benzophenone, ethylhexyl dimethyl PABA, 4-methylbenzylidene camphor, benzyl salicylate, and isoamyl methoxycinnamate were found at lower yet relevant concentrations. UV filters banned under European regulations, such as menthyl anthranilate and etocrylene, were absent or barely detected. This work provides the first data on sunscreen UV filters in Adriatic coastal waters and the first quantitative evidence of Z-EHMC in environmental waters, highlighting its in situ formation and contributing to understanding their environmental fate and risks.

The potential adverse effects, including systemic reactions, of some organic filters used in sunscreens have driven the search for alternatives. Brazilian green propolis, rich in polyphenols, shows promise in absorbing ultraviolet (UV) radiation and acting as an antioxidant in photoprotective formulations, allowing for a reduction in the concentration of organic filters while maintaining photoprotection efficacy. Oil-in-water emulsions were prepared containing chemical UV filters-ethylhexyl methoxycinnamate and butyl methoxydibenzoylmethane-with or without the addition of Brazilian green propolis extract at concentrations of 2.5 % and 5.0 % (w/w), along with a blank formulation as control. These formulations were assessed for antioxidant activity, photoprotective efficacy (in vitro and in vivo methods), photostability, inhibition of lipid peroxidation in the stratum corneum of human volunteers, and skin permeability. The addition of green propolis extract significantly enhanced both the antioxidant activity and sun protection factor (SPF) of the formulations without significant penetration, making it an excellent alternative to partially replace organic filters. In vitro photoprotective efficacy parameters met broad-spectrum sunscreen standards, providing good to excellent ultraviolet A (UVA) protection. However, the low photostability of the formulations limited the extract's ability to protect the stratum corneum from lipid peroxidation. Therefore, Brazilian green propolis serves as a promising adjuvant in sunscreen formulation, boosting efficacy while ensuring formulation safety.

Hair growth cosmeceuticals (HGCs) for women have become increasingly popular. We sought to analyze the ingredients of HGCs and their potential environmental hazards. A cross-sectional study was conducted using a Google Boolean search to identify the top 10 nonsponsored articles on HGCs. After applying exclusion criteria, 58 unique HGCs marketed as either unisex or female products were analyzed. Ingredients were documented from product websites, and HGCs were categorized based on specific ingredients with potential environmental concerns. The study found that phenoxyethanol (32.8%) and synthetic fragrances (25.9%) were the most common ingredients with potential environmental implications, with trisodium Ethylenediaminetetraacetic acid (EDTA), trisodium ethylenediamine disuccinate, isobutane, butane, n-butane, ethylhexyl methoxycinnamate, and benzophenone-4 also found. Ingredients such as sodium lauryl sulfate, parabens, and microbeads were, however, not found in any of the products evaluated. The study was limited by potential reporting and sampling bias. Significant environmental hazards, particularly to aquatic habitats, have been associated with specific ingredients commonly found in HGCs.

Skincare is an increasing concern, as ultraviolet (UV) radiation causes skin diseases and photoaging, increasing demand for photoprotective personal care products (PCPs). PCPs contain UV filters, namely ecamsule (ECA), 2-ethylhexyl 4-methoxycinnamate (EHMC) and octocrylene (OC), and parabens, such as propylparaben (PPb) and methylparaben (MPb). These enter the environment, posing toxicity risks to marine species. Ecotoxicity screening of multiple contaminants is resource-intensive, making in vitro alternatives valuable. We assessed the toxicity of these chemicals (0, 50, 500, 5000 ng/L) using S9 subcellular fractions from Mytilus galloprovincialis digestive glands (DG) and gills (G) after acute (30 min) in vitro exposure. Antioxidant enzymes activities decreased after exposure to EHMC and both parabens. OC triggered an increase in glutathione peroxidase activity. Carboxylesterases activity was inhibited in G exposed to EHMC and both parabens, whereas higher ECA concentrations increased the activity in DG. An increase in glutathione-S-transferase activity occurred in G exposed to MPb and the highest PPb concentration. Neurotoxicity occurred in DG exposed to EHMC and ECA, and in G exposed to EHMC, PPb and MPb. EHMC and both parabens elicited the strongest responses in the antioxidant and biotransformation systems, cellular damages and neurotoxicity. This study demonstrates that exposure to environmentally relevant concentrations of cosmetic chemicals may lead to impairments within S9 subcellular fraction, which may compromise mussels' survival.

Plastic debris in marine environments serves as a substrate for microbial colonisation, forming biofilms known as 'plastispheres'. Also accumulated on plastic debris are co-pollutants including UV-protective organic UV-filters from sunscreens, which likely interact with this niche through their lipophilicity. Despite their widespread use and environmental accumulation, the influence of UV-filters on plastisphere composition and function has never been investigated. This study therefore investigates, for the first time, how co-pollution - specifically by an organic UV-filter - impacts the composition and function of marine plastisphere communities. To achieve this, low-density polyethylene (LDPE) was incubated with marine microbial communities for six days to cultivate a nascent plastisphere, which was then exposed to 5 mg/L of EthylHexyl MethoxyCinnamate (EHMC); the most used organic UV-filter in sunscreens, and a prevalent marine pollutant. Metagenomic analyses revealed that EHMC favoured the growth of bacterial generalists Pseudomonas and Psychromonas while reducing pollutant-degrading genera like Marinomonas. Analysis of 3070 proteins revealed a consistent upregulation of proteins used for biofilm maintenance by Pseudomonas with EHMC exposure, including the considerable upregulation of outer membrane porin F (OprF) which regulates exopolymeric substance (EPS) production. Additionally, proteins thought to indicate a shift from aerobic to anaerobic respiration were frequently expressed after exposure to EHMC. This may have selected against the obligate aerobes Marinomonas and Pseudoalteromonas, contributing to the observed shift in community composition. These findings underscore the importance of considering chemical co-pollutants in plastisphere research as we now begin to discover how ecologically significant, and potentially harmful microbial genera are affected by this interaction.

Ultraviolet (UV) filters are emerging contaminants of great concern that are widely used in personal care products (PCPs). In this study, the concentrations of 15 UV filters in six types of PCP marketed in China were analyzed and the health risks posed by their internal and external exposure were evaluated. 2-ethylhexyl-4-methoxycinnamate (EHMC) presented the highest median concentration of 3150 ng/g in PCPs, followed by 2-ethylhexyl salicylate (109 ng/g) and octocrylene (OC, 95.1 ng/g). The total UV filter concentrations were considerably higher in sunscreens than other PCPs. Total external dermal exposure to UV filters in sunscreen was higher than the total estimated daily dietary intake of UV filters. A physiologically based toxicokinetic model to predict internal UV filter concentrations after sunscreen application for 1 d showed that EHMC had the highest predicted maximum concentration in venous blood at 0.0770 ng/mL, only one order of magnitude lower than the reference dose. The predicted maximum UV filter concentrations were higher for high-lipid-content tissues than venous blood, consistent with UV filters being lipophilic. OC, EHMC and homosalate made large contributions to the toxic activity assay results, and thus should receive more attention than other UV filters.

The photodynamics of a given chromophore are usually affected by the surrounding environment (e.g., solvent or matrix). As a result, it is often assumed that the 'fundamental' spectroscopic behavior of a given chromophore, usually studied in dilute solution, is not relevant to the understanding of more complex mixtures. In this work, we demonstrate that the 'fundamental' photodynamics of common sunscreen UV filters are comparable to those observed in formulation, including the complex interactions between them, and even for formulation applied to a skin mimic. In particular, we have carried out ultrafast laser spectroscopy studies directly on sunscreen formulations containing methyl anthranilate (MA), ethylhexyl methoxycinnamate (EHMC), and octocrylene (OCR) as commonly used UV filters. Our results not only have significant implications for the sunscreen industry, providing direct evidence of UV filter interactions in formulation, but importantly they are demonstrative of the relevance of 'fundamental' spectroscopic techniques to understanding real-life systems.

Exposure to ultraviolet (UV) radiation is a major contributor to skin injury, including sunburn, photoaging, and augmented risk of skin cancer, primarily through the generation of reactive oxygen species (ROS) that induce oxidative stress. Rosmarinic acid (RA), a natural phenolic compound with antioxidant and several other biological properties, has shown promise in mitigating such damage when incorporated into sunscreens. We evaluated RA's possible interactions and potential to enhance the efficacy of three worldwide known UVB filters-ethylhexyl methoxycinnamate (EHMC), octocrylene (OCT), and ethylhexyl salicylate (EHS). The performance of sunscreens with and without RA (0.1% w / w ) was analyzed through in vitro and in vivo photoprotective assessments. The HPLC-TBARS-EVSC (high-performance liquid chromatography-thiobarbituric acid reactive substances-ex vivo stratum corneum) protocol, which quantified oxidative stress reduction in the human stratum corneum, was also used. The in vitro photoprotective assays showed that RA had distinct levels of interactions with the UVB filters. When associated with EHMC, RA exclusively acted in the UVB range (SPF-enhancing effect). Remarkably, for EHS, RA contributed to a higher efficacy profile in the total UV spectrum. OCT-RA was the sample that reached the highest critical wavelength value parallelly to OCT, boosting the in vivo SPF by more than 157% in comparison to OCT. However, its in vitro SPF performance was not affected by the RA addition, being comparable to OCT, EHS, and EHS-RA. Furthermore, the HPLC-TBARS-EVSC protocol highlighted RA's ability to reduce lipid peroxidation, with OCT-RA exhibiting the most notable protective effect. These findings underscore RA's potential as a multifunctional additive in sunscreen systems, enhancing both photoprotection and oxidative stress mitigation.