You can learn more about how we ensure our content is accurate and current by reading our. Sruthi S., Mohanan P.V. Decreased iron and calcium, but not Zn, sodium and potassium levels in rat brain homogenates; unchanged emotional behavior. Its best to avoid Hawaiian Tropic, as they seem to be partaking in greenwashing: while their products use a seal and claim to be reef-friendly, it isnt a real certification. Therapeutic refers to sunscreens where the primary use is sun protection and has an SPF of 4 or higher. Cho W.-S., Kang B.-C., Lee J.K., Jeong J., Che J.-H., Seok S.H. Analysis by Sharifan et al. Rai R, et al. Average mass 310.387 Da. Data from 2003 indicate that over 80% sunscreen products contained OMC, 60% contained BP-3, and 20% contained octocrylene (OC) or HMS, whereas inorganic filters were present in around 20% of products [39]. Whether concentration resulted from daily use and/or environmental contact possesses a realistic hazard to humans and other organisms is still unknown. ZnO NPs induced apoptosis via the PI3K/Akt/caspase-3/7 pathway and necrosis by lipoxygenase (LOX)-mediated ROS production [118]. Cytotoxicity and ROS generation in glioma lines, but not in normal human astrocytes. The main non-biodegradable ingredients used in sunscreen include: Butyl methoxydibenzoylmethane; Paraffinum liquidum Decreased hypothalamic release of LHRH. For this reason, avobenzone is now often formulated with photostabilising chemicals such as octocrylene and bemotrizinole. When adults applied a sunscreen formulation containing 10% of BP-3, 4-methylbenzylidene camphor (4-MBC) and octyl methoxycinnamate (OMC) on a daily basis (2mg/cm2) for a week, the mean urine concentrations for these ingredients were 60, 5, 5ng/ml for females and 140, 7, 8ng/ml for males, respectively [19]. DOI: Huglin D. (2016). Accumulation in brain with ROS and cell death in hypothalamus. These results can be explained by the great stability and low ionizing capacity of these particles and are in accordance with several studies in the literature [159], [160], [161]. Changes in CAT, SOD, GPx activity, GSH levels and lipid peroxidation was also observed in the brain and other organs of juvenile carp (Cyprinus carpio) exposed to waterborne ZnO NPs (0.5, 5, 50mg/l) for 1, 3, 7, 10 and 14days [107]. Just make sure to avoid oxybenzone or octinoxate in particular. contributed to bleaching and poisoning coral reefs, 8 and 9. While this ingredient has been in European circulation since 1993, the FDA didnt approve this ingredient for LOral until 2006. Week-long oral administration of ZnO NPs (600mg/kg) to male Wistar rats resulted in decreased brain CAT, GPx, and GR activities, decreased GSH and SOD levels, but elevated malondialdehyde (MDA) level and inflammatory markers: TNF-, IL-1, IL-6, C-reactive protein (CRP). Details The famous Avobenzone. Han D., Tian Y., Zhang T., Ren G., Yang Z. Nano-zinc oxide damages spatial cognition capability via over-enhanced long-term potentiation in hippocampus of Wistar rats. Advanced UV absorbers for the protection of human skin. Neurotoxic effect of active ingredients in sunscreen products, a Other reviews discuss absorption, distribution, metabolism and excretion of ZnO NPs in humans and experimental models more extensively [12], [79], [82]. Distribution of the UV filter 3-benzylidene camphor in rat following topical application. Gulson B., Mccall M.J., Bowman D.M., Pinheiro T. A review of critical factors for assessing the dermal absorption of metal oxide nanoparticles from sunscreens applied to humans, and a research strategy to address current deficiencies. ZnO NPs (2.510g/ml) induced cytotoxicity in rat retinal ganglion cells (RGC-5) and inhibited cell proliferation in a time- and concentration-dependent manner. Thus, they also are emergent as an environmental pollutant [40]. Elevated ROS levels, altered antioxidant system, increased DA and NE levels, presence of ZnO NPs in neurons. Wood E. (2018). Furthermore, low cytotoxicity observed in human HaCaT keratinocytes, suggests a low toxic potential of these nano-compounds at the skin level. It is, however, unclear how high levels might occur in environment and if they are harmful to organisms [129]. [134] described the in vivo uptake and clearance of TiO2 NPs by BECs and demonstrated a Ti burden in the liver, spleen and lungs up to a year after intravenous (i.v.) A wider range of ultraviolet light wavelengths can be absorbed by avobenzone. Your email address will not be published. The levels of BP-3 detected in coral reefs in the U.S. Virgin Islands (751400g/l) and Hawaii (0.819.2g/l) might lead to death of several local coral species with LC50: 8340g/l and LC20: 0.0628g/l (4h exposure) [33]. Moreover, with increased usage and lack of efficient removal, environmental contamination will probably increase in the future. Organic filters can be classified by the type of ultraviolet (UV) radiation they absorb, namely UVB, UVA or UVB-UVA filters (Table 1). Wang J.X., Li Y.F., Zhou G.Q., Li B., Jiao F., Chen C.Y., Gao Y.X., Zhao Y.L., Chai Z.F. Moderate skin sunburn increased the penetration of ZnO NPs in pigs, however transdermal absorption was not detected [90]. [26]. (2008). Ansar S., Abudawood M., Hamed S.S., Aleem M.M. Molins-Delgado D., Gago-Ferrero P., Diaz-Cruz M.S., Barcelo D. Single and joint ecotoxicity data estimation of organic UV filters and nanomaterials toward selected aquatic organisms. Oxidative stress was also present in rat PC12 cells exposed to TiO2 NPs 50g/ml for 24h (P25 type, 21nm in average size) and N-(2-mercaptopropionyl)-glycine (N-MPG), a kind of ROS scavenger, prevented apoptosis in this model [145], indicating that oxidative stress is an important factor in TiO2 NPs-induced neurotoxicity. Most of the significant perturbations occurred in organic acids (citric, lactic, fumaric, succinic and malic acids) and amino acids. Janjua N.R., Mogensen B., Andersson A.M., Petersen J.H., Henriksen M., Skakkebaek N.E., Wulf H.C. Toxicity of bulk-scale (160nm) and nanoscale (21nm) TiO2 was tested under dark and light conditions. Influence of intranasal instilled titanium dioxide nanoparticles on monoaminergic neurotransmitters of female mice at different exposure time. Impaired learning and memory abilities, suppression of cAMP/CREB signaling pathway. Inhibition of AChE activity was also observed in mammalian Neuro-2a cells exposed to 10 and 100M for 45min, indicating a possible mechanism for the 4-MBC-induced muscular and neuronal defects [57]. Schlumpf M., Kypke K., Wittassek M., Angerer J., Mascher H., Mascher D., Vkt C., Birchler M., Lichtensteiger W. Exposure patterns of UV filters, fragrances, parabens, phthalates, organochlor pesticides, PBDEs, and PCBs in human milk: correlation of UV filters with use of cosmetics. Impact of 4-methylbenzylidene-camphor (4-MBC) during embryonic and fetal development in the neuroendocrine regulation of testicular axis in prepubertal and peripubertal male rats. Avobenzone - an overview | ScienceDirect Topics Concentration-dependent decrease in cell viability; apoptosis, necrosis, release of zinc ions. Sunscreening agents: A review. Exposure to zinc oxide nanoparticles induces neurotoxicity and proinflammatory response: amelioration by hesperidin. Microarray showed significant alterations of 249 genes expression involved in oxidative stress, apoptosis, memory and learning, brain development, lipid metabolism, DNA repair, signal transduction, immune response and response to stimulus in the brain-injured mice. Effects dependent on TiO, U373 human glial cells and C6 rat glial cells. It's not just the ingredients. The effect of UV-filters on the viability of neuroblastoma (SH-SY5Y) cell line. As mentioned previously, the main route of human exposure is dermal absorption, however other routes and environmental exposure should be also considered. Amara S., Ben-Slama I., Mrad I., Rihane N., Jeljeli M., El-Mir L., Ben-Rhouma K., Rachidi W., Sve M., Abdelmelek H., Sakly M. Acute exposure to zinc oxide nanoparticles does not affect the cognitive capacity and neurotransmitters levels in adult rats. Biodegradation of the ZnO:Eu nanoparticles in the tissues of adult mouse after alimentary application. Most recently, a study found that our skin absorbs sunscreen ingredients like oxybenzone. Thus, increasing usage, persistent input and accumulation in environment is becoming an issue of great concern because of threat to human health, but also to the environment. Of importance, some UV filters were also found in human milk samples. Schlumpf M., Cotton B., Conscience M., Haller V., Steinmann B., Lichtensteiger W. In vitro and in vivo estrogenicity of UV screens. Hello Bello might have the best sunscreen products for the environment but if youre not able to buy them you might need more options. Skocaj M., Filipic M., Petkovic J., Novak S. Titanium dioxide in our everyday life; is it safe? Moreover, part of the absorbed UV radiation can generate free radicals on the surface of metal oxides in the presence of water and this photocatalytic activity increases with decreasing NPs size. BP-3 was detected in more than 80% of urine samples of healthy Danish children and adolescents (median concentration 0.92ng/ml) [66]. 4-MBC is a high lipophilic component which can be absorbed through the skin and was found in human tissues, including placenta [70]. Thompson S.C., Jolley D., Marks R. Reduction of solar keratoses by regular sunscreen use. While this is only one harmful ingredient, octocrylene in large concentrations can harm aquatic ecosystems. Yin Y., Lin Q., Sun H., Chen D., Wu Q., Chen X., Li S. Cytotoxic effects of ZnO hierarchical architectures on RSC96 Schwann cells. Alongside the evidence for increasing levels of these agents in the environment, which leads to indirect exposure of wildlife and humans, recent studies suggest a toxicological nature for some of these agents. Vielhaber G, et al. Most studies demonstrated that ZnO NPs did not penetrate into deeper layers of the skin (SC) [83], [84], [22], [85], [86]. Morphological changes associated with depolymerization of F-actin, apoptotic cell death. The most common mineral sunscreens use zinc oxide or titanium oxide. Sunscreen: Does SPF Matter and Which One Should I Choose? An official website of the United States government. Seborg T., Ganderup N.C., Kristensen J.H., Bjerregaard P., Pedersen K.L., Bollen P., Hansen S.H., Halling-Srensen B. increased formation of micronuclei. Kajta M., Wjtowicz A.K. Generally, the risk of ZnO NPs exposure from dermal absorption is rather low, however, considering a common human behavior related to sunscreen application, e.g. The detrimental effects of exposure to UVA and UVB rays, which can cross the epidermis, have been reviewed and it was concluded that such exposure leads to reactive oxygen species (ROS) generation, DNA/protein/lipid damage, activation of various signal transduction pathways, compromised skin defense systems, altered growth, differentiation, senescence and tissue degradation, to name a few [5], [6], [7]. Topics AZ A172, U87, LNZ308, LN18, LN229 glioma cell lines and normal human astrocytes. Schreurs R., Lanser P., Seinen W., Van Der Burg B. Estrogenic activity of UV filters determined by an in vitro reporter gene assay and an in vivo transgenic zebrafish assay. Effects of nanoparticle zinc oxide on spatial cognition and synaptic plasticity in mice with depressive-like behaviors. In vitro studies reported similar findings, only a limited number of ZnO NPs were found on the outer surface of the SC, and no particles were observed in the deeper SC layers [83], [84]. Kao Y.Y., Cheng T.J., Yang D.M., Wang C.T., Chiung Y.M., Liu P.S. Angelstorf J.S., Ahlf W., Von der kammer F., Heise S. Impact of particle size and light exposure on the effects of TiO2 nanoparticles on Caenorhabditis elegans. Photodegredation is delayed by mixing avobenzone with stabilizing chemicals. While the sunscreens sold by Blue Lizard are all mineral-based, they have no commitment to being environmentally friendly and its possible that they use other petroleum-based chemicals. Repeated (4days) topical applications (2mg/cm2 of sunscreen formulation) of BP-3 resulted in urine levels up to 81ng/ml and plasma levels up to 238ng/ml [20]. The United States classification of sunscreen as a drug is one of the biggest reasons for its slow approval rate. DIY sunscreens on Pinterest are extremely popular, ec.europa.eu/health/ph_risk/committees/04_sccp/docs/sccp_o_058.pdf, tga.gov.au/book/2-therapeutic-sunscreen-or-cosmetic-sunscreen, accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=352.50, link.springer.com/epdf/10.1007/s00244-015-0227-7?shared_access_token=lRAXkGu1XApz6jHGNg_CNPe4RwlQNchNByi7wbcMAY5VYCT4UGN4uI8dnS0bV8Myv9mGCAftDf32vi0At8e_HNV_0wDMrNSDE8HCVaz3KpLtw0WYOKvHY93rYFXVgoJs2A_m3_qp9PKL61Zo3QOX4_J4-SWyNXIbE1k8OohKL4Q=, fda.gov/news-events/press-announcements/fda-advances-new-proposed-regulation-make-sure-sunscreens-are-safe-and-effective, ncbi.nlm.nih.gov/pmc/articles/PMC1831786/, ingentaconnect.com/contentone/scs/chimia/2016/00000070/00000007/art00002?crawler=true, ncbi.nlm.nih.gov/pmc/articles/PMC3543289/, accessdata.fda.gov/drugsatfda_docs/nda/2006/021502s000_Anthelios_SX_MedR.pdf, jamanetwork.com/journals/jama/article-abstract/2733085, researchgate.net/publication/283515177_An_overview_of_sunscreen_regulations_in_the_world, ncbi.nlm.nih.gov/pmc/articles/PMC3482794/, fda.gov/drugs/guidance-compliance-regulatory-information/regulatory-policy-information-sunscreen-innovation-act, ncbi.nlm.nih.gov/pmc/articles/PMC5615097/, ncbi.nlm.nih.gov/pmc/articles/PMC3423755/, ncbi.nlm.nih.gov/pmc/articles/PMC3781714/, skincancer.org/prevention/sun-protection/sunscreen/sunscreens-explained, jamanetwork.com/journals/jamadermatology/fullarticle/1105240, icriforum.org/sites/default/files/ICRI_Sunscreen_0.pdf, Why You Need to Reconsider That Sunscreen Youre Using. administration of TiO2 NPs (1mg/kg) to rats, with a very low clearance rate. It is able to absorb the full spectrum of UVA rays and has been around since the 1980s in sunscreen formulations worldwide. Titanium dioxide nanoparticle penetration into the skin and effects on HaCaT cells. In zebrafish larvae exposed to environmentally relevant concentrations (110g/ml) of TiO2 NPs induced Parkinson's disease (PD)-like symptoms, with locomotor alteration, reduced DA, Lewy bodies formation and alterations in mRNA levels of pink1, parkin and -syn, that were significantly increased in a dose-dependent manner. As a mineral ingredient, zinc oxide can be found naturally as the mineral zincite. Ze Y., Hu R., Wang X., Sang X., Ze X., Li B., Su J., Wang Y., Guan N., Zhao X., Gui S., Zhu L., Cheng Z., Cheng J., Sheng L., Sun Q., Wang L., Hong F. Neurotoxicity and gene-expressed profile in brain-injured mice caused by exposure to titanium dioxide nanoparticles. The authors suggested that TiO2 NPs stimulated microglia produced inflammatory factors, which caused PC12 cells cytotoxicity [146]. effective sunscreens use chemicals that are toxic to coral reefs, oxybenzone contaminate water from swimming, factors contribute to the toxicity of hydrogen peroxide in fish, biodegradable sunscreens are made with mostly natural or otherwise environmentally safe ingredients, bans in places like Hawaii, Palau, and Thailand, ingredients that cause harm to aquatic environments to avoid according to the HEL LIST, Bare Republic mineral SPF 50 sport sunscreen stick, Sun Bum Mineral SPF 50 sunscreen roll-on lotion, Hello Bello is upfront about their commitment to being reef-safe, Hello Bello SPF 50 kids mineral sunscreen lotion, Hello Bello SPF 55+ sunscreen mineral lotion, Hello Bello SPF 30 kids mineral sunscreen spray, potentially degrade into a toxin and potential carcinogen known as acrylamide, Raw Elements face and body certified natural sunscreen with non-nano zinc oxide, Badger SPF 30 baby sunscreen cream with zinc oxide, Badger SPF 30 active mineral sunscreen cream. Avobenzone is a dibenzoylmethane derivative and is a chemical substance that is used in sunscreen products. Federal government websites often end in .gov or .mil. In fact, Kao et al. Studies that describe the specific proteins that carry TiO2 to and/or from the brain are lacking. Dareer E.L.S.M., Kalin J.R., Tillery K.F., Hill D.L. It is used in sunscreen products in EU, at a maximal concentration of 2% [1]. In this review, the potential neurotoxicity of such substances is presented and the question of cost-benefit is raised regarding large scale use of sunscreen in its current composition. Some mineral sunscreens use other ingredients which make them non-biodegradable and environmentally harmful, but most genuine mineral-based sunscreens are safe for the environment. This observation questions the safety of ZnO NPs exposure during pregnancy, potential transfer through placenta and the effect on developing brain. Long-term intake of TiO2 NPs at low doses was assayed in rats. Monteiro-Riviere N.A., Wiench K., Landsiedel R., Schulte S., Inman A.O., Riviere J.E. Because TiO2 accumulated in worm intestines, as observed by microscopy, the authors suggested that ROS were formed extracellularly in the apical surface of the worms intestinal cells [141]. Broniowska ., Pomierny B., Smaga I., Filip M., Budziszewska B. If You Use SPF Moisturizer, Youre Probably Making This Mistake. Debacq-Chainiaux F., Leduc C., Verbeke A., Toussaint O. UV, stress and aging. octyl methoxycinnamate (OMC), benzophenone-3 (BP-3) or octocrylene (Table 1), which absorb light in the UV range, and inorganic (physical) filters, zinc oxide (ZnO) and titanium dioxide (TiO2), which scatter and reflect UV rays. This may not always be because of the ingredients themselves. Shrivastava R., Raza S., Yadav A., Kushwaha P., Flora S.J.S. When the size of TiO2 is diminished to nanoscale (diameter <100nm), the bioactivity and physiochemical properties of nano-sized TiO2 are significantly different from the properties of their bulk analogue [127], [128]. The neurotoxic effects were partially reversed by the antioxidant and anti-inflammatory compound, hesperidin [102]. However, studies simulating real-world scenarios on sunburned skin, with UV exposure in long-term chronic exposure conditions need to be conducted to assure the safety of TiO2 in sunscreen. Oxidative stress and disrupted antioxidant system is another effect observed in brains of ZnO NPs-treated animals. Systematic influence induced by 3nm titanium dioxide following intratracheal instillation of mice. Several in vitro and in vivo studies evaluated the fate and toxicity of ZnO NPs from different exposures: dermal, gastrointestinal or pulmonary. Some of their products also use octinoxate, one of the most harmful chemicals to coral reefs. Disposition of 2-hydroxy-4-methoxybenzophenone in rats dosed orally, intravenously, or topically. 4mg/kg, biweekly for 8 weeks) Wistar rats. There are several types of electromagnetic radiation emitted by the sun. Inclusion in an NLM database does not imply endorsement of, or agreement with, BP-3), whereas ng to g/l range were detected in lake and sea water. ZnO NPs induced parkin protein translocation from the cytoplasm to the mitochondria, implying the involvement of mitophagy in ZnO NPs-induced toxicity [125]. A time- and concentration-dependent cytotoxicity characterized by apoptosis and increased ROS production was also observed in ZnO NPs-treated (580g/ml) C6 glial cells [122]. At the same time, maximum plasma concentrations for these ingredients, reached 34h after application, were 200, 20, 10ng/ml for females and 300, 20, 20ng/ml for males, respectively. Authors suggested that observed changes might result from the Zn2+ dissolved in solution or intracellularly, rather than from NPs, since ZnO NPs were not detectable in apoptotic cells, and similar cytotoxicity was observed after treatment with ZnCl2 Ovariectomized rats exposed to 57.5mg/20g body weight of OMC applied via food presented a decrease in thyroxine (T4) levels without changes in triiodothyronine (T3) or thyroid-stimulating hormone (TSH) levels [60]. An overview of endocrine disrupting properties of UV-filters. Benzophenone-4 (BP-4, sulisobenzone) is frequently used as UV absorber at concentration up to 10% [1]. Physical sunscreens made with zinc oxide or titanium dioxide block UV rays from the skin, and they wont wash off easily because theyre oil soluble. Morphological changes associated with depolymerization of F-actin were found, accompanied by apoptotic cell death [143]. ZnO NP-induced cytotoxicity was also observed in microglia (BV-2 cells) exposed to 10g/ml ZnO NPs for 224h [125]. Philippat C., Bennett D., Calafat A.M., Picciotto I.H. In Australia, sunscreen is classified as therapeutic or cosmetic. Contact and photocontact allergy to octocrylene: a review. In contrast, in the liver, some of these genes (vtg1, vtg3) were down-regulated [52]. Dermal absorption is the most relevant entry route of chemicals related to sunscreen use. HHS Vulnerability Disclosure, Help Release of ROS, mitochondrial hyperpolarization, BV2 microgial cells, N27 neurons, primary cultures of rat striatum, Microglia generated ROS damages neurons in complex primary cultures. Reef-safe sunscreens are any sunscreens that dont contain oxybenzone or octinoxate. However, these mineral filters, when in normal pigment size range (200400nm for ZnO, 150300nm for TiO2) have poor particle dispersion, which makes them difficult to apply; they also reflect and scatter light, which result in undesirable visible white film on the skin. Inflammatory cell aggregation and neuron necrosis. Australian Gold sunscreens are paraben and PABA-free, but their sunscreens all use octocrylene. In the case of TiO2 NPs, it is not yet clear how they are transported into or out of the brain, how they accumulate or what kind of behavioral or cognitive dysfunction they may cause, however the evidence summarized in this (Table 4) and other review articles [130], [128], [79], [149], [150], [151], [152], [153], [154] may indicate that their toxic potential remains to be fully elucidated. Zhang X., Li W., Yang Z. Toxicology of nanosized titanium dioxide: an update. PC12 rat pheochromocytoma and SH-SY5Y human neuroblastoma. 8600 Rockville Pike A single 1030min inhalation of a high dose (2042mg/m3) of ZnO NPs aerosol increased levels of the inflammatory cytokines interleukin (IL)-6, IL-8, and tumor necrosis factor (TNF-) in bronchoalveolar lavage fluid within 3h after exposure in humans Kuschner et al., 1997. Reports and research show that DIY sunscreens on Pinterest are extremely popular, despite the fact that DIY sunscreens dont work and can, in fact, increase skin damage. In healthy human adults inhaling 500g/m3 of ZnO NPs for 2h, the results were below the threshold for acute systemic effects on the respiratory, hematologic, and cardiovascular endpoints [92]. In vitro, oxybenzone has antiandrogenic as well as proestrogenic and antiestrogenic effects. Required fields are marked *. Miranda R.R., Damaso Da Silveira A.L.R., De Jesus I.P., Grtzner S.R., Voigt C.L., Campos S.X., Garcia J.R.E., Randi M.A.F., Oliviera Ribeiro C.A., Filipak Neto F. Effects of realistic concentrations of TiO2 and ZnO nanoparticles in Prochilodus lineatus juvenile fish. Mineral-based sunscreens use inorganic material to reflect, scatter, and absorb UV light. Moreover, their antiseptic activity makes them potentially useful in treatment of bacteria-related infections or diseases [81]. Wlaschek M., Tantcheva-Por I., Naderi L., MAW, Schneider L.A., Razi-Wolf Z., Schller J., Scharffetter-Kochanek K. Solar UV irradiation and dermal photoaging. The Banned Sunscreen Ingredients and Their Impact on Human Health: A 110g/ml). Chemical UV filters are easily absorbed by the skin and reach the systemic circulation, and accumulate in various tissues, as adipose tissue, liver and the brain [41], [42], [43], [44]. This caused a spike of interest in safe sunscreens, despite the study reporting no harm found and concluding that these results do not indicate that individuals should refrain from the use of sunscreen.. (2018). Occupational exposures to TiO2 NPs have been reported more frequently and was summarized in a recent review, demonstrating that the respirable TiO2 concentration in the workers breathing zone might reach 150g/m3 Time-correlated single photon counting for simultaneous monitoring of zinc oxide nanoparticles and NAD(P)H in intact and barrier-disrupted volunteer skin. Alterations in behavior and PD-related genes. As their commercial utilization has increased, wider application raises the potential risk of human exposure [82]. Studies on animals have also shown certain levels of toxicity, leading the European Commission and the FDA to restrict formula concentrations to 5 percent. Prez S., Farr M.L., Barcel D. Analysis, behavior and ecotoxicity of carbon-based nanomaterials in the aquatic environment. Different types of ZnO NPs (coated <200nm and uncoated <30nm) (1080g/ml, incubated for 2, 6 or 24h) induced cytotoxicity in human olfactory neurosphere-derived (hONS) cells via mechanisms associated with cell stress, inflammation and apoptosis [114]. The range of light that is scattered as well as other properties of TiO2 depend on the particle size. Octyl methoxycinnamate (OMC) is a UVB filter also known as octinoxate and 2-ethylhexyl 4-methoxy cinnamate.