Interested in knowing more?

• Coral animals are tiny and live together in communities that often look like rock to us. But they are not rocks. They are living things.
• Even if you never go in the ocean, chemicals from sunscreens can find their way there in beachside communities.  Water from pools, showers, and baths, drain through pipes to treatment plants that are unable to remove the sunscreen chemicals.  From the treatment facilities, the chemicals ride in the treated water into rivers and streams and for beachside communities, directly into oceans.  
• When using a spray sunscreen that contains chemicals, those chemicals are being sprayed all over, including onto the sand at a beach.  At high tide, the water comes in over the sand and those chemicals are let loose into the ocean.
• Sunscreens with chemicals have been found to cause coral bleaching.  One of the worst is Oxybenzone (Benzophenone-3 (BP-3)) which leaches the coral of its nutrients and bleaches it white (coral bleaching), causes DNA damage, acts as a skeletal endochrine disruptor, and causes deformities in baby coral.  
• The chemicals in chemical sunscreens are absorbed by the skin of people and go into the bloodstream. Some of these chemicals are known to cause hormone disruption. 
• When faced with shelves of sunscreens, to find a safe one you can start by checking the ones made for babies like Neutrogena Baby and ones featuring zinc like Raw Elements Zinc.
• Every person matters.  The more people visiting a reef or nearby beach, the more danger there is to coral from sunscreen.

Reading the labels:

• If it has the "Protect Land + Sea Certification" seal with the turtle image, it is lab-tested and safe for the reef and the rest of the ocean as well.   
• If it says "Reef Safe" or "Reef Friendly" it is worth a closer look, but the phrases aren't regulated so check the ingredients to be sure it really is safe for coral reefs.
• If it says "Natural", that phrase is not meaningful or regulated.  Look at the ingredients.
• "Non-nano" is good. In reference to zinc oxide and titanium dioxide it means the mineral particles are too big to be ingested by coral.  Even regular zinc oxide or titanium dioxide is better than chemicals.
• If a sunscreen has both good and bad ingredients, it is still bad.

More about mineral sunscreens:

• Mineral sunscreens sit on top of the skin.
• Nano and non-nano refer to the size of the zinc or titanium particles.  The size of the particles affects the way they look on the skin (white vs transparent) and their affect on coral (whether they can be ingested).  Both nano and non-nano are really small particles, non-nano is a way to refer to particles that aren't as tiny.  Non-nano, being on the larger size are better for coral, they can't be ingested.  People tend to like nano mineral sunscreens with their really tiny particles so that the sunscreen will be less noticeable on their skin.  Regardless of particle size, mineral sunscreens are better than chemical ones for the coral and for people.
• All forms of mineral sunscreen are not equal.  The minerals should be intended for sunscreen use and have a special surface coating.  Choose a reputable company.
• Zinc Oxide is considered more effective than Titanium Dioxide because Zinc Oxide protects very well against both UVA and UVB rays. Titanium Dioxide is considered more effective than Titanium Oxide.

How to use less sunscreen:

• In the water, you can wear a long sleeve "rash guard" which is a thin synthetic material shirt made to wear in the water.  It can protect your arms, chest, and back from the sun and helps protect you from getting scrapped up on sand and other rough underwater things.
• Wear a broad brimmed hat to protect your face and neck.
• Wear light cotton clothing to cover yourself.
• Sit under an umbrella or in the shade (note that sunlight reflects off of sand and water so shade is rarely enough at the beach.  Wear clothing too.)

There are multiple threats to coral reefs, it's not just sunscreen:

• Higher water temperatures due to climate change.
• Discharges and runoff from sewer pipes (all kinds of chemicals not captured by treatment facilities), runoff from properties (fertilizers, pesticides, etc), and from construction (silt).
• People who stand on coral (it's not a rock, it's alive).

Main Sources:

• Haereticus Environmental Laboratory (HEL): a non-profit scientific organization dedicated to increasing the scientific, social and economic knowledge of natural environmental habitats in order to better conserve and restore threatened environmental habitats and resources.
• National Ocean Services of NOAA (National Ocean and Atmospherice Administration)
• The study from the journal Archives of Environmental Contamination and Toxicology: February 2016, "Toxicopathological Effects of the Sunscreen UV Filter, Oxybenzone (Benzophenone-3), on Coral Planulae and Cultured Primary Cells and Its Environmental Contamination in Hawaii and the U.S. Virgin Islands"