Chemical SPFs include Benzophenone, Oxybenzone, Octinoxate, Octocrylene, Avobenzone, and Homosalate. They work by changing UV rays into heat through a chemical reaction, then release that heat from the skin. Clean SPFs like Zinc Oxide and Titanium Dioxide create a physical barrier layer on the skin to block UV rays.
These chemicals can be found in everything from moisturizers, sprays, creams, foundations, tinted moisturizers, liquid bronzers, shampoo, nail polish, lip products, and more. They are linked to hormonal disruption + often an acne trigger. Chemical SPF also has diminishing efficacy over time.
Chemical Sunscreens are banned in the Florida island of Key West, the US state of Hawaii, the US Virgin Islands, The Caribbean island of Bonaire, the archipelago nation of Palau, as well as The Mexican Nature Reserves Xel Ha, Xcaret Park, and Garrafon Natural Reef Park due to their toxicity and damaging effects on reef health.
[1] Scientific American. Chemical SPF ban in Hawaii. (2018). https://www.scientificamerican.com/article/why-is-hawaii-banning-sunscreen/
[2] American Cancer Society. Oxybenzone. (2018). https://www.cancer.org/latest-news/how-safe-is-your-sunscreen.html
[3] NCBI, NIH. Krause M et al., Sunscreens: are they beneficial for health? An overview of endocrine disrupting properties of UV-filters. International Journal of Andrology, vol. 35, no. 3, pp 424-436. (2012). https://www.ncbi.nlm.nih.gov/pubmed/22612478
[4] NCBI. NIH. Kim T, et al. Percutaneous absorption, disposition, and exposure assessment of homosalate, a UV filtering agent in rats. Journal of Toxicology and Environmental Health, Part A, vol. 77, no.4, pp 202-213. (2014). https://www.ncbi.nlm.nih.gov/pubmed/24555679
[5] Kunz P, Fent K. Multiple hormonal activities of UV filters and comparison of in vivo and in vitro estrogenic activity of ethyl-4-aminobenzoate in fish. Aquatic Toxicology, vol. 79, pp 305-324. (2006). https://europepmc.org/article/med/21356179
[6] NBCI. NIH. S.L. Schneider, H.W. Lim, Department of Dermatology, Henry Ford Hospital, Detroit, Michigan. Octinoxate, Octocrylene. (2014). https://www.ncbi.nlm.nih.gov/pubmed/29981751