Skip to main content

Sunscreen Safety: a Review of Recent Studies on Humans and the Environment

Abstract

Purpose of Review

To provide an up-to-date synopsis of the literature on the safety of sunscreen active ingredients in humans and the environment and highlight regulatory changes in the USA.

Recent Findings

Currently, as per the US Food and Drug Administration, the only ultraviolet filters generally recognized as safe and effective are inorganic zinc oxide (ZnO) and titanium dioxide (TiO2). In vivo human systemic absorption studies found that common organic filters attain sufficient plasma concentrations to require carcinogenicity and reproductive studies. In vivo human skin penetration studies showed ZnO nanoparticles (ZnO-NP) did not penetrate the stratum corneum. Limited quantities of TiO2-NP may be absorbed systemically. In laboratory settings, corals exposed to oxybenzone manifested concentration-dependent toxicity and bleaching. In response, bills passed in Hawaii and elsewhere ban sales of oxybenzone-containing sunscreens. ZnO-NP, but not TiO2-NP, caused coral bleaching under controlled conditions.

Summary

The collective knowledge on sunscreen safety is continually evolving, with many preliminary findings. Studies on the effects of systemic absorption of organic filters in humans are forthcoming; importantly, there has been no evidence of harm over decades of use. Organic (less so inorganic) filters caused coral bleaching in controlled environments, but filter concentrations may not have been realistic, and bleaching is predominantly driven by other factors. No present evidence suggests any marketed sunscreens should be avoided. For consumers with concerns, inorganic ZnO and TiO2 are supported by the most reassuring data at the time of writing.

This is a preview of subscription content, access via your institution.

References

Papers of particular interest, published recently, have been highlighted as: •• Of major importance

  1. Young AR, Claveau J, Rossi AB. Ultraviolet radiation and the skin: photobiology and sunscreen photoprotection. J Am Acad Dermatol. 2017;76(3s1):S100–s9. https://doi.org/10.1016/j.jaad.2016.09.038.

    CAS  Article  Google Scholar 

  2. Yeager DG, Lim HW. What’s new in photoprotection: a review of new concepts and controversies. Dermatol Clin. 2019;37(2):149–57. https://doi.org/10.1016/j.det.2018.11.003.

    CAS  Article  PubMed  Google Scholar 

  3. Mancuso JB, Maruthi R, Wang SQ, Lim HW. Sunscreens: an update. Am J Clin Dermatol. 2017;18(5):643–50. https://doi.org/10.1007/s40257-017-0290-0.

    Article  PubMed  Google Scholar 

  4. Centers for Disease Control and Prevention. Sun safety. https://www.cdc.gov/cancer/skin/basic_info/sun-safety.htm. Accessed October 4 2019.

  5. World Health Organization. Sun protection. https://www.who.int/uv/sun_protection/en/. Accessed October 6 2019.

  6. American Cancer Society. Choose the right sunscreen. https://www.cancer.org/latest-news/choose-the-right-sunscreen.html. Accessed October 6 2019.

  7. American Academy of Dermatology. Say yes to sun protection. https://www.aad.org/public/spot-skin-cancer/learn-about-skin-cancer/prevent/say-yes-to-sun-protection. Accessed October 4 2019.

  8. Skin Cancer Foundation. Sunscreen. https://www.skincancer.org/skin-cancer-prevention/sun-protection/sunscreen/. Accessed October 4 2019.

  9. DeLeo VA. Sunscreen regulations and advice for your patients. Cutis. 2019;103(5):251–3.

    PubMed  Google Scholar 

  10. Calafat AM, Wong LY, Ye X, Reidy JA, Needham LL. Concentrations of the sunscreen agent benzophenone-3 in residents of the United States: National Health and Nutrition Examination Survey 2003–2004. Environ Health Perspect. 2008;116(7):893–7. https://doi.org/10.1289/ehp.11269.

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  11. Wang J, Pan L, Wu S, Lu L, Xu Y, Zhu Y, et al. Recent advances on endocrine disrupting effects of uv filters. Int J Environ Res Public Health. 2016;13(8). https://doi.org/10.3390/ijerph13080782.

  12. Ghazipura M, McGowan R, Arslan A, Hossain T. Exposure to benzophenone-3 and reproductive toxicity: a systematic review of human and animal studies. Reprod Toxicol. 2017;73:175–83. https://doi.org/10.1016/j.reprotox.2017.08.015.

    CAS  Article  PubMed  Google Scholar 

  13. Ruszkiewicz JA, Pinkas A, Ferrer B, Peres TV, Tsatsakis A, Aschner M. Neurotoxic effect of active ingredients in sunscreen products, a contemporary review. Toxicol Rep. 2017;4:245–59. https://doi.org/10.1016/j.toxrep.2017.05.006.

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  14. Wang SQ, Burnett ME, Lim HW. Safety of oxybenzone: putting numbers into perspective. Arch Dermatol. 2011;147(7):865–6. https://doi.org/10.1001/archdermatol.2011.173.

    Article  PubMed  Google Scholar 

  15. Hayden CG, Roberts MS, Benson HA. Systemic absorption of sunscreen after topical application. Lancet. 1997;350(9081):863–4. https://doi.org/10.1016/s0140-6736(05)62032-6.

    CAS  Article  PubMed  Google Scholar 

  16. Grande F, Tucci P. Titanium dioxide nanoparticles: a risk for human health? Mini-Rev Med Chem. 2016;16(9):762–9. https://doi.org/10.2174/1389557516666160321114341.

    CAS  Article  PubMed  Google Scholar 

  17. •• Schneider SL, Lim HW. A review of inorganic UV filters zinc oxide and titanium dioxide. Photodermatol Photoimmunol Photomed. 2018. https://doi.org/10.1111/phpp.12439Review of human and environmental safety concerns related to ZnO and TiO2UV filters.

  18. Filipe P, Silva JN, Silva R, Cirne de Castro JL, Marques Gomes M, Alves LC, et al. Stratum corneum is an effective barrier to TiO2 and ZnO nanoparticle percutaneous absorption. Skin Pharmacol Physiol. 2009;22(5):266–75. https://doi.org/10.1159/000235554.

    CAS  Article  PubMed  Google Scholar 

  19. Osmond MJ, McCall MJ. Zinc oxide nanoparticles in modern sunscreens: an analysis of potential exposure and hazard. Nanotoxicology. 2010;4(1):15–41. https://doi.org/10.3109/17435390903502028.

    CAS  Article  PubMed  Google Scholar 

  20. Senjen R. Submission regarding SCCS opinion on zinc oxide (nano form), 2012. https://ntn.org.au/wp-content/uploads/2012/11/NTA-SCCS-submission-Oct-2012-1.pdf. Accessed October 16 2019.

  21. US Food and Drug Administration. Nonprescription sunscreen drug products—safety and effectiveness data; Guidance for Industry; Availability. Fed Regist. 2016;81(226):84594–5.

    Google Scholar 

  22. US Food and Drug Administration. Sunscreen drug products for over-the-counter human use: proposed rule. Fed Regist. 2019;84(38):6204–75.

    Google Scholar 

  23. Nelson R. Final OTC Sunscreen monograph postponed, FDA Leadership Confirms https://hbw.pharmaintelligence.informa.com/RS149446/Final-OTC-Sunscreen-Monograph-Postponed-FDA-Leadership-Confirms. Accessed November 30 2019.

  24. •• Matta MK, Zusterzeel R, Pilli NR, Patel V, Volpe DA, Florian J, et al. Effect of sunscreen application under maximal use conditions on plasma concentration of sunscreen active ingredients: a randomized clinical trial. JAMA. 2019;321(21):2082–91. https://doi.org/10.1001/jama.2019.5586Open-label, randomized human study demonstrating that within one day, four common organic UV filters applied according to label instructions in a controlled environment were detected in plasma at concentrations exceeding those set by the FDA to require further toxicity studies.

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  25. Califf RM, Shinkai K. Filling in the evidence about sunscreen. JAMA. 2019;321(21):2077–9. https://doi.org/10.1001/jama.2019.5528.

    Article  PubMed  Google Scholar 

  26. American Academy of Dermatology. American Academy of Dermatology comments on recent study on absorption of sunscreen ingredients https://www.aad.org/media/news-releases/study-sunscreen-ingredients. Accessed October 7 2019.

  27. •• Hiller J, Klotz K, Meyer S, Uter W, Hof K, Greiner A, et al. Systemic availability of lipophilic organic UV filters through dermal sunscreen exposure. Environ Int. 2019;132:105068. https://doi.org/10.1016/j.envint.2019.105068In a one-day real-life human exposure scenario, organic UV filters reached higher absolute plasma concentrations compared to a longer but more environmentally controlled trial.

    CAS  Article  PubMed  Google Scholar 

  28. •• Mohammed YH, Holmes A, Haridass IN, Sanchez WY, Studier H, Grice JE, et al. Support for the safe use of zinc oxide nanoparticle sunscreens: lack of skin penetration or cellular toxicity after repeated application in volunteers. J Invest Dermatol. 2019;139(2):308–15. https://doi.org/10.1016/j.jid.2018.08.024In healthy human skinin vivo, there was no evidence that coated or uncoated ZnO-NP applied to limited body surface area for up to five days penetrated below the stratum corneum or caused cellular toxicity or apoptosis.

    CAS  Article  PubMed  Google Scholar 

  29. Gulson B, McCall M, Korsch M, Gomez L, Casey P, Oytam Y, et al. Small amounts of zinc from zinc oxide particles in sunscreens applied outdoors are absorbed through human skin. Toxicol Sci. 2010;118(1):140–9. https://doi.org/10.1093/toxsci/kfq243.

    CAS  Article  PubMed  Google Scholar 

  30. Gulson B, Wong H, Korsch M, Gomez L, Casey P, McCall M, et al. Comparison of dermal absorption of zinc from different sunscreen formulations and differing UV exposure based on stable isotope tracing. Sci Total Environ. 2012;420:313–8. https://doi.org/10.1016/j.scitotenv.2011.12.046.

    CAS  Article  PubMed  Google Scholar 

  31. Wright PFA. Realistic exposure study assists risk assessments of ZnO nanoparticle sunscreens and allays safety concerns. J Invest Dermatol. 2019;139(2):277–8. https://doi.org/10.1016/j.jid.2018.09.014.

    CAS  Article  PubMed  Google Scholar 

  32. •• Pelclova D, Navratil T, Kacerova T, Zamostna B, Fenclova Z, Vlckova S, et al. NanoTiO2 Sunscreen does not prevent systemic oxidative stress caused by UV radiation and a minor amount of NanoTiO2 is absorbed in humans. Nanomaterials (Basel). 2019;9(6). https://doi.org/10.3390/nano9060888In human subjects, sunscreen containing TiO2-NP failed to prevent oxidative stress or inflammation in UV-exposed skin. Low quantities of TiO2-NP were detected in plasma and urine six hours following application, but local skin penetration was not proven definitively.

  33. Naess EM, Hofgaard A, Skaug V, Gulbrandsen M, Danielsen TE, Grahnstedt S, et al. Titanium dioxide nanoparticles in sunscreen penetrate the skin into viable layers of the epidermis: a clinical approach. Photodermatol Photoimmunol Photomed. 2016;32(1):48–51. https://doi.org/10.1111/phpp.12217.

    Article  PubMed  Google Scholar 

  34. •• Schneider SL, Lim HW. Review of environmental effects of oxybenzone and other sunscreen active ingredients. J Am Acad Dermatol. 2019;80(1):266–71. https://doi.org/10.1016/j.jaad.2018.06.033Comprehensive appraisal of the data concerning environmental impact of organic UV filters.

    CAS  Article  PubMed  Google Scholar 

  35. Tsui MM, Leung HW, Wai TC, Yamashita N, Taniyasu S, Liu W, et al. Occurrence, distribution and ecological risk assessment of multiple classes of UV filters in surface waters from different countries. Water Res. 2014;67:55–65. https://doi.org/10.1016/j.watres.2014.09.013.

    CAS  Article  PubMed  Google Scholar 

  36. •• Downs CA, Kramarsky-Winter E, Segal R, Fauth J, Knutson S, Bronstein O, et al. Toxicopathological Effects of the Sunscreen UV Filter, Oxybenzone (Benzophenone-3), on Coral Planulae and Cultured Primary Cells and Its Environmental Contamination in Hawaii and the U.S. Virgin Islands. Arch Environ Contam Toxicol. 2016;70(2):265–88. https://doi.org/10.1007/s00244-015-0227-7In laboratory conditions, coral larvae exposed to oxybenzone at concentrations similar to and higher than those in seawater manifested signs of toxicity, mortality, and bleaching, helping spur sunscreen ingredient bans, despite objections to the realistic applicability of these findings.

    CAS  Article  PubMed  Google Scholar 

  37. Danovaro R, Bongiorni L, Corinaldesi C, Giovannelli D, Damiani E, Astolfi P, et al. Sunscreens cause coral bleaching by promoting viral infections. Environ Health Perspect. 2008;116(4):441–7. https://doi.org/10.1289/ehp.10966.

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  38. Galamgam J, Linou N, Linos E. Sunscreens, cancer, and protecting our planet. Lancet Planet Health. 2018;2(11):e465–e6. https://doi.org/10.1016/s2542-5196(18)30224-9.

    Article  PubMed  Google Scholar 

  39. Heron SF, Eakin CM, Douvere F, Anderson KL, Day JC, Geiger E, et al. Impacts of climate change on World Heritage coral reefs: a first global scientific assessment. Paris: UNESCO World Heritage Centre; 2017.

    Google Scholar 

  40. Hawaii State Legislature. S.B. No. 2571. Relating to water pollution. https://www.capitol.hawaii.gov/session2018/bills/SB2571_CD1_.htm. Accessed October 21 2019.

  41. Xu VX. Palau bans many kinds of sunscreen, Citing Threat to Coral New York Times. 2018.

  42. Filosa G. Key West bans the sale of sunscreens that hurt coral reefs in the Keys. Miami Herald. 2019.

  43. Forgione M. U.S. Virgin Islands’ ban on harmful sunscreens to go into effect Jan. 1 Los Angeles Times. 2019.

  44. Beitsch R. Sunscreen bans aimed at protecting coral reefs spark debate—among scientists. Washington Post. 2019.

  45. Wood E. Impacts of sunscreens on coral reefs. Report by the International Coral Reef Initiative (ICRI) 2018. https://www.icriforum.org/sites/default/files/ICRI_Sunscreen_0.pdf. Accessed October 21 2019.

  46. •• Sirois J. Examine all available evidence before making decisions on sunscreen ingredient bans. Sci Total Environ. 2019;674:211–2. https://doi.org/10.1016/j.scitotenv.2019.04.137Response from industry to legislation prohibiting sale and distribution of organic UV filters.

    CAS  Article  PubMed  Google Scholar 

  47. Hughes TP, Kerry JT, Baird AH, Connolly SR, Dietzel A, Eakin CM, et al. Global warming transforms coral reef assemblages. Nature. 2018;556(7702):492–6. https://doi.org/10.1038/s41586-018-0041-2.

    CAS  Article  PubMed  Google Scholar 

  48. Cyronak T, Andersson AJ, Langdon C, Albright R, Bates NR, Caldeira K, et al. Taking the metabolic pulse of the world’s coral reefs. PLoS One. 2018;13(1):e0190872. https://doi.org/10.1371/journal.pone.0190872.

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  49. Marques JA, Costa PG, Marangoni LFB, Pereira CM, Abrantes DP, Calderon EN, et al. Environmental health in southwestern Atlantic coral reefs: geochemical, water quality and ecological indicators. Sci Total Environ. 2019;651(Pt 1):261–70. https://doi.org/10.1016/j.scitotenv.2018.09.154.

    CAS  Article  PubMed  Google Scholar 

  50. Bruno JF, Valdivia A. Coral reef degradation is not correlated with local human population density. Sci Rep. 2016;6:29778. https://doi.org/10.1038/srep29778.

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  51. Rodgers KS, Bahr KD, Jokiel PL, Richards DA. Patterns of bleaching and mortality following widespread warming events in 2014 and 2015 at the Hanauma Bay Nature Preserve. Hawai’i PeerJ. 2017;5:e3355. https://doi.org/10.7717/peerj.3355.

    Article  PubMed  Google Scholar 

  52. Mitchelmore CL, He K, Gonsior M, Hain E, Heyes A, Clark C, et al. Occurrence and distribution of UV-filters and other anthropogenic contaminants in coastal surface water, sediment, and coral tissue from Hawaii. Sci Total Environ. 2019;670:398–410. https://doi.org/10.1016/j.scitotenv.2019.03.034.

    CAS  Article  PubMed  Google Scholar 

  53. Skin Cancer Foundation. What the Skin Cancer Foundation wants people to know about Hawaii’s proposed ban on the sale and distribution of sunscreens containing oxybenzone and octinoxate. https://www.skincancer.org/press/2018-hawaii-proposed-ban-on-sunscreen-oxybenzone-and-octinoxate/. Accessed October 21 2019.

  54. Mirsky RS, Prado G, Svoboda RM, Rigel DS. Oxybenzone and sunscreens: a critical review of the evidence and a plan for discussion with patients. Skin-J Cutan Med. 2018;2(5):264-8. https://doi.org/10.25251/2.5.0.

  55. Zirwas MJ, Andrasik W. Can sunscreens harm coral reefs? Addressing environmental concerns and offering practical recommendations. Skinmed. 2018;16(4):223–9.

    PubMed  Google Scholar 

  56. Tsatalis J, Burroway B, Bray F. Evaluation of “reef safe” sunscreens: labeling and cost implications for consumers. J Am Acad Dermatol. 2019. https://doi.org/10.1016/j.jaad.2019.11.001.

  57. •• Corinaldesi C, Marcellini F, Nepote E, Damiani E, Danovaro R. Impact of inorganic UV filters contained in sunscreen products on tropical stony corals (Acropora spp.). Sci Total Environ. 2018;637–638:1279–85. https://doi.org/10.1016/j.scitotenv.2018.05.108Coral fragments showed evidence of bleaching when exposed to ZnO-NP, but not TiO2-NP, in a controlled environment using filter concentrations that may have been unrealistically high.

    CAS  Article  PubMed  Google Scholar 

  58. Jovanovic B, Guzman HM. Effects of titanium dioxide (TiO2 ) nanoparticles on caribbean reef-building coral (Montastraea faveolata). Environ Toxicol Chem. 2014;33(6):1346–53. https://doi.org/10.1002/etc.2560.

    CAS  Article  PubMed  Google Scholar 

  59. Hanigan D, Truong L, Schoepf J, Nosaka T, Mulchandani A, Tanguay RL, et al. Trade-offs in ecosystem impacts from nanomaterial versus organic chemical ultraviolet filters in sunscreens. Water Res. 2018;139:281–90. https://doi.org/10.1016/j.watres.2018.03.062.

    CAS  Article  PubMed  Google Scholar 

Download references

Acknowledgments

The authors wish to thank Drs. Jeffrey Weinberg and Jonathan Silverberg for reviewing their manuscript.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Brandon L. Adler.

Ethics declarations

Conflict of Interest

The authors declare no conflict of interest.

Human and Animal Rights and Informed Consent

This article does not contain any studies with human or animal subjects performed by any of the authors.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

This article is part of the Topical Collection on Photodermatology

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Adler, B.L., DeLeo, V.A. Sunscreen Safety: a Review of Recent Studies on Humans and the Environment. Curr Derm Rep 9, 1–9 (2020). https://doi.org/10.1007/s13671-020-00284-4

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s13671-020-00284-4

Keywords

  • Sunscreen
  • Sunblock
  • Oxybenzone
  • Benzophenone-3
  • Avobenzone
  • Octocrylene
  • Ecamsule
  • Zinc oxide
  • ZnO
  • Titanium dioxide
  • TiO2
  • Nanoparticle
  • NP
  • Human
  • Health
  • Safety
  • Toxicity
  • Systemic absorption
  • FDA
  • GRASE
  • Regulation
  • Environment
  • Ecosystem
  • Coral reef
  • Bleaching
  • Ban
  • Hawaii