Stability of chemical UV filters in sunscreens exposed to vehicle cabin temperatures

Leslie K. Dennis 1, 2, *, Alesia M. Jung1, Kelly A. Reynolds2,3, Chiu-Hsieh Hsu1, Leif Abrell 4,5

1Department of Epidemiology and Biostatistics, Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ, USA.2University of Arizona’s Environmental Exposure Science and Risk Assessment Center (ESRAC), Tucson, AZ, USA.3 Department of Community, Environment & Policy, Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ, USA.  4Department of Chemistry and Biochemistry, College of Science, University of Arizona, Tucson, AZ, USA.5Department of Environmental Science, College of Agricultural and Life Sciences, University of Arizona, Tucson, AZ, USA.

Background: Sunscreen companies recommend replacing your chemical sunscreen every year.  Consumer inquiries about product integrity under excessive exposure to heat prompted the FDA to add a requirement statement to sunscreen products indicating a need to protect stored sunscreen from excessive heat and direct sun. If heat exposure indeed affects chemical sunscreen stability, then in some areas, replacement may be warranted earlier than a year.

Methods: We examined real-life scenarios related to the storage of sunscreen containers inside vehicles sitting in natural sunlight to provide information about the stability of sunscreen active ingredients under real-life storage conditions.  The active ingredients avobenzone, oxybenzone, homosalate, octinoxate, octisalate, and octocrylene in samples of sunscreens were examined after heat exposure over six months using liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis.  The calculated levels of each active ingredient were then compared between the non-heat exposed samples and the heat exposed samples using a paired t-test to look for decreases in active chemicals from heat exposure.

Results: No important differences were seen for heat exposure in this study of 378 hours of temperatures above 37.8 °C, with an additional 292 hours of exposure to temperatures of 32.2-37.7 °C, and 3454 hours at 26.7-32.2 °C.

Conclusions: This suggests such heat exposure does not result in degradation of the active ingredients of sunscreens with sun protection factors (SPF) of 30 and 50. This is important for individuals attempting to prevent sunburns and skin cancer.

Keywords: heat; photochemistry; photoprotection; sunscreen.

Free Full-text PDF

How to cite this article:
Leslie K. Dennis, Alesia M. Jung, Kelly A. Reynolds, Chiu-Hsieh Hsu, Leif Abrell. Stability of chemical UV filters in sunscreens exposed to vehicle cabin temperatures.American Journal of Dermatological Research and Reviews, 2021, 4:46. DOI: 10.28933/ajodrr-2021-06-0805


1. U.S. Department of Health and Human Services. The Surgeon General’s Call to Action to Prevent Skin Cancer. Washington, DC: U.S. Dept of Health and Human Services, Office of the Surgeon General; 2014.
2. Gandini S, Sera F, Cattaruzza MS, Pasquini P, Zanetti R, Masini C, Boyle P, Melchi CF. Meta-analysis of risk factors for cutaneous melanoma: III. Family history, actinic damage and phenotypic factors. Eur J Cancer. 2005;41(14):2040-59.
3. Khalesi M, Whiteman DC, Tran B, Kimlin MG, Olsen CM, Neale RE. A meta-analysis of pigmentary characteristics, sun sensitivity, freckling and melanocytic nevi and risk of basal cell carcinoma of the skin. Cancer Epidemiol. 2013;37(5):534-43.
4. Alam M, Ratner D. Cutaneous squamous-cell carcinoma. N Engl J Med. 2001;344(13):975-83.
5. Armstrong BK, Kricker A. The epidemiology of UV induced skin cancer. J Photochem Photobiol B. 2001; 63(1-3): 8-18
6. Gandini S, Sera F, Cattaruzza MS, Pasquini P, Picconi O, Boyle P, Melchi CF. Meta-analysis of risk factors for cutaneous melanoma: II. Sun exposure. Eur J Cancer. 2005;41(1):45-60.
7. MacKie. Long-term health risk to the skin of ultraviolet radiation. Prog Biophys Mol Biol. 2006; 92(1): 92–96.
8. Dennis LK, VanBeek MJ, Beane Freeman LE, Smith BJ, Dawson DV, Coughlin JA. Sunburns and risk of cutaneous melanoma: Does age matter? A comprehensive meta-analysis. Ann Epidemiol. 2008; 18(8):614-27. [PMID: 18652979].
9. Holman DM, Ding H, Guy GP Jr, Watson M, Hartman AM, Perna FM. Prevalence of Sun Protection Use and Sunburn and Association of Demographic and Behavioral Characteristics with Sunburn Among US Adults. JAMA Dermatol. 2018; 154(5):561-568. PMID: 29541756; PMCID: PMC5876912.
10. Food and Drug Administration, Department of Health and Human Services. Sunscreen drug products for over-the-counter human use; final monograph. Final rule. Fed Regist. 1999; 64(98):27666-93.
11. Food and Drug Administration, Department of Health and Human Services. Guidance for Industry Labeling and effectiveness testing; sunscreen drug products for over-the-counter human use. Final rule. Fed Regist. 2011; 76(117):35620-65.
12. Bronfenbrener R. Simplifying sun safety: a guide to the new FDA sunscreen monograph. Cutis. 2014; 93(4):E17-9.
13. Hexsel CL, Bangert SD, Hebert AA, Lim HW. Current sunscreen issues: 2007 Food and Drug Administration sunscreen labelling recommendations and combination sunscreen/insect repellent products. J Am Acad Dermatol. 2008; 59(2):316-23.
14. Australian Government, Department of Health, Therapeutic Goods Administration. Australian regulatory guidelines for sunscreens (ARGS). 2019. Version 1.2.
15. de la Coba F, Aguilera J, Korbee N, de Gálvez MV, Herrera-Ceballos E, Álvarez-Gómez F, Figueroa FL. UVA and UVB Photoprotective Capabilities of Topical Formulations Containing Mycosporine-like Amino Acids (MAAs) through Different Biological Effective Protection Factors (BEPFs). Mar Drugs. 2019; 17(1):55. doi: 10.3390/md17010055.
16. Food and Drug Administration, Department of Health and Human Services. Sunscreen drug products for over-the-counter human use. Fed Regist. 2019. 84 (38): 6204-75.
17. Roscher NM, Lindemann MKO, Kong SB, Cho CG, Jiang P. Photodecomposition of several compounds commonly used as sunscreen agents. J Photochem Photobiol A: Chem. 1994; 80: 417-21.
18. Jung GW, Ting PT, Salopek TG. Stability of sunscreens and sunblocks following exposure to extreme temperatures. J Am Acad Dermatol. 2012:66;1007-1009.
19. Smaoui S, Hlima HB, Chobba IB, Kadri A. Development and stability studies of sunscreen cream formulations containing three photo-protective filters. Arabian Journal of Chemistry. 2013, doi:10.1016/j.arabjc.2013.02.020.
20. Briasco B, Capra P, Mannucci B, Perugini P. Stability Study of Sunscreens with Free and Encapsulated UV Filters Contained in Plastic Packaging. Pharmaceutics 2017, 9, 19; doi:10.3390/pharmaceutics9020019
21. Anaya-Esparza LM, Villagran-de la Mora Z, Ruvalcaba-Gómez JM, Romero-Toledo R, Sandoval-Contreras T, Aguilera-Aguirre S, Montalvo-González AE, Pérez-Larios A. Use of titanium dioxide (TiO2) nanoparticles as reinforcement agent of polysaccharide-based materials. Processes 2020; 8:1395. doi:10.3390/pr8111395
22. The Old Farmer’s Almanac 2021. Yankeee Publishing. 2020. 308 p. ISBN-13: 978-1-57198-848-5 (ISBN-10: 1571988483). Last accessed 10/7/2020.
23. Gagliardi L, Amato A, Basili A, Cavazzutti G, Tonelli D. Determination of sun-screen agents in cosmetic products by reversed-phase high-performance liquid chromatography. J Chromatogr. 1987;408:409-415.
24. Bratkovics S, & Sapozhnikova Y. Determination of seven commonly used organic UV filters in fresh and saline waters by liquid chromatography-tandem mass spectrometry. Anal Methods. 2011;3(12):2943-50.
25. Grundstein A, Meentemeyer V, Dowd J. Maximum vehicle cabin temperatures under different meteorological conditions. Int J Biometeorol. 2009;53(3):255-261.

Terms of Use/Privacy Policy/ Disclaimer/ Other Policies:
You agree that by using our site, you have read, understood, and agreed to be bound by all of our terms of use/privacy policy/ disclaimer/ other policies (click here for details)

CC BY 4.0
This work and its PDF file(s) are licensed under a Creative Commons Attribution 4.0 International License.