A few specific UV filters, as found in commercially available sun creams, are suspected of damaging coral reefs. Recent laboratory studies have linked the ingredient oxybenzone (benzophenone-3) to coral damage, which can lead to coral bleaching or coral death when sufficiently concentrated. Corals can survive a bleaching event, but are then more stressed and more likely to die. For another ingredient, octinoxate (ethylhexyl methoxycinnamate), the research is less conclusive, but the mechanism could be similar.
In response to the research, Hawaii became the first US state to pass a law prohibiting the sale of sunscreen products containing the UV filters oxybenzone and octinoxate. The law will come into force on January 1, 2021 – from that date on, sunscreen products containing these ingredients will be prohibited for sale in Hawaii.