This is an important topic and so I want to get the most important things out of the way first: Chemical sunscreens containing the following ingredients contribute to coral bleaching: Oxybenzone Octinoxate Octocrylene (used to also stabilize avobenzone) 4-methylbenzylidine camphor Anything containing Parabens Don't be part of the problem and avoid using them! It's important to note that claims on sunscreens are not regulated and therefore, companies can put the wording "coral reef safe" on the packaging even though they contain the above chemicals. This is misleading if not outright false. Instead use "physical" sun screens that contain non-nanoparticle zink oxide. Physical sun screens differ from chemical sunscreens in that the sit ontop of the skin to reflect or scatter UVA/B rays away from the skin before it reaches it. Chemical sunscreens absorb the UVA/B rays instead to neutralize them. To be clear, I am not proposing not using sunscreen! I