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Is My Sunscreen Reef Safe?

There’s a lot of controversy out there regarding which chemicals are damaging our corals. Did you know there are also sunscreens claiming to be “reef safe” with no scientific backing?! How can you tell the difference when you can’t even pronounce the ingredients? Scientists are conducting new studies all the time but I’ll try and break down the most recent results to provide you with some guidelines on what chemicals to avoid.


This chemical has been proven hands down to be the leading cause of coral bleaching found in sunscreen. It’s causing extensive damage not only to the reef itself, but also disrupts coral reproduction. Hawai’i has passed a ban on oxybenzone but it doesn’t go into effect until 2020, which means it will be sold in stores until then. Keep a lookout and avoid.

Octinoxate / Octocrylene

These chemicals are also known to cause coral bleaching and
should be avoided.


This is a preservative that causes coral bleaching. Avoid.

4-methylbenzylidene camphor (4-MBC)

This chemical isn’t sold in the USA or Japan, but it is in
Canada and Europe. It’s known to bleach coral. Avoid.

Titanium Dioxide

This chemical has caused some controversy. A lot of sunscreens on the market labeled “Reef Safe” contain this ingredient. The problem with it is that it isn’t water soluble. Titanium stays in the ocean forever, never biodegrading. It settles on the ocean floor, moving along as sediment and therefore suffocates living organisms. There is no evidence that it causes bleaching of the coral, but it is seen as an ocean pollutant. If you purchase sunscreen containing this ingredient, be sure it’s a NON-NANO titanium dioxide. This form is better at adhering to your skin, so less comes off while you are swimming. This also means it doesn’t rub in as well, so expect a whitish hue on all areas you apply.

Zinc Oxide

Same results have been found for zinc oxide as titanium dioxide. This ingredient is in the majority of “reef safe” sunscreens. Please limit use to NON-NANO zinc oxide.

Spray-on Sunscreen

Even reef safe sunscreens come in the spray bottle variety. This is NOT an environmentally friendly method of sunscreen application. Next time you see someone applying spray sunscreen, notice the cloud of mist that blows down wind. That mist is all wasted sunscreen. A good portion of the product purchased never even protects someone from the sun! It just ends up in the atmosphere. I’d avoid spray on sunscreen if for no other reason than to save money well spent.

Final Thoughts

As with all products we apply to our hair and skin, what doesn’t rub off throughout the day ends up being washed off in the shower. Please keep in mind the quote from Finding Nemo: “All drains lead to the ocean!” Even if you are merely hiking or shell collecting, that sunscreen ends up in a drain, which ends up back in our water supply or in our oceans. I highly recommend investing in clothing that offers sun protection as well. There are many styles to choose from at all price points. Mahalo nui for your time, interest and compassion for our beautiful coral reefs!

*Disclaimer: There have been many more chemicals studied and shown to cause damage to coral. They haven’t been included in this list because studies have had conflicting results. Each laboratory conducts their study using different criteria. This creates differing results which don’t always line up with other laboratory studies. The chemicals I have listed are more universally accepted. Again, new studies are being done all the time, so the results are ongoing. I encourage everyone to keep up on the research so as to shop responsibly. Thank you!