It is estimated that 25% of the sunscreen we apply to our bodies ends up in the water. A number of scientific publications have attempted to map the effects of various UV filters on the environment, with some chemicals - including Benzophenone-3, Ethylhexyl Methoxycinnamate, Octocrylene, Ethylhexyl Salicylate, Butyl Methoxydibenzoylmethane and Homosalate - identified as particularly hazardous to ecosystems. These cause, among other things, coral to become more susceptible to bleaching, to deform and to become less resilient to climate change.
The US Virgin Islands recently adopted a ban on the import, sale and possession of sunscreen products containing the active ingredients Bensophenone-3, Ethylhexyl Methoxycinnamate and Octocrylene. Hawaii and Key West in Florida are also ready to ban the use of Bensophenone-3 and Ethylhexyl Methoxycinnamate in sunscreen products. However, in the rest of the US both filters are still allowed (Benophenone-3 at a maximum level of 6%, the same as in the EU). The EU has so far not restricted the use of UV filters because of their negative environmental impact.
The more skin-friendly mineral filters, titanium dioxide and zinc oxide, have also been shown to adversely affect aquatic organisms such as fish, algae and crustaceans, so their use alone is not preferable from an environmental perspective.
The situation is complex, but to adequately protect yourself from the sun, our advice is to use a sunscreen that contains a combination of safe modern organic filters as well as mineral filters. But remember, don't rely entirely on sunscreen; avoid the strongest sun during the day, wear protective clothing hats, sunglasses and take care of your skin.