
If you vacation in an area with protected coral reefs you might notice that wearing sunscreen in the water is banned outright or that only certain sunscreens are permitted. Why so? Well some research shows that many common ingredients found in the most popular sunscreens bleach and kill coral reefs. Fortunately, Block Island Organics does not use these ingredients.
One of the first links between sunscreen and the health of our oceans comes from a 2003 study published in Microbial Ecology. The study showed that some sunscreens damage plankton. Now, thanks largely to a 2008 study in the journal Environmental Health Perspectives, it's apparent that some sunscreens also damage coral reefs.
Beauty and Benefits of Coral Reefs
The true beauty, value and environmental impact of a coral reef is much more than can be seen with the naked eye. On the surface we see coral reefs as beautiful displays of marine life full of colorful fish, corals, underwater plants, and other living organisms.
However, the complexity of coral reefs far exceeds there outward beauty. As the EPA explains, corals are actually tiny animals belonging to the same family as jelly fish and sea anemones. Some corals even feed by using tentacles to reach out and catch pray such as small fish and planktonic animals.
Scientists consider coral reefs one of the most diverse ecosystems in the world and often call coral reefs the “rainforests of the oceans.” As we all learned in elementary school our environment depends on a circle or balance of ecosystems. This is why the destruction of coral reefs has a far-reaching effect. In fact over a half billion people are directly sustained by coral reefs according to the National Oceanic and Atmospheric Administration (NOAA).
Disappearance of Coral Reefs
In recent years scientists have focused more on the disappearance of coral reefs. One 2008 study showed approximately sixty percent of coral reefs are threatened due to a myriad of factors and a 2007 study showed that our reefs are disappearing at rates twice that of tropical rain forests.
The same 2008 study in the journal Environmental Health Perspectives estimates that 4,000 to 6,000 metric tons of sunscreen wash off swimmers annually in oceans worldwide, and up to 10 percent of coral reefs are directly threatened by sunscreen-induced bleaching.
Besides sunscreen, factors affecting the health of coral reefs include rising ocean temperatures and increased fishing. While it's said and likely true that these factors are are a larger cause the damage to coral reefs, we say why not also avoid chemical sunscreen too.
Study Results: Sunscreen and Coral Reefs

© Department of Marine Science, Polytechnic University of Marche, Ancona, Italy
Yes, certain sunscreens, including many of the most popular brands, can and do kill our coral reefs. A handful of common ingredients used in sunscreens are the culprit.
The aforementioned 2008 study identified seven common sunscreen ingredients for testing. Four of those ingredients caused complete bleaching of coral reefs even at low concentrations. What we mean by bleaching is this: a living coral reef has a dark color which is representative of an algae that is alive and living in coral tissue.
This algae provides the coral reef with energy thru photosynthesis. Sunscreen ingredients are killing this algae by awakening dormant viruses in the algae which then replicate until the algae explodes or the algae is released by the coral tissue. As a result the virus is then spread into surrounding waters where it can infect more coral reef tissue. Once the algae explodes or is released the coral reef dies and turns a white color. The other three ingredients tested had little or no impact on coral reefs.
Ingredients to Avoid to Protect Coral Reefs
The four ingredients found to bleach coral reefs are: benzophenones, cinnamates, camphor derivatives, and parabens. These are all ingredients commonly found in chemical sunscreens and some mineral sunscreens. Block Island Organics does not use any of these ingredients.
Look for the ingredients oxybenzone and dioxybenzone on the back of your chemical sunscreen; these are benzophenone derivatives used in chemical sunscreens to block UV rays. Best to avoid them.
Cinnamates, which may be listed as octyl methoxycinnamate, cinoxate, octinoxate, or ethylhexyl methoxycinnamate, are commonly used UVB absorbing ingredients in chemical sunscreens and are also often found in makeup products that contain SPF. Again, another ingredient to be wary of.
The camphor derivative really being referred to here is 4MBC, aka 4-methylbenzylidene camphor, which is a chemical UV filter not approved as an active ingredient in U.S. sunscreens but allowed as an inactive ingredient. So check for it there and stay away if you see it.
Finally parabens are used in both chemical and mineral sunscreens as a cheap preservative. You are more likely to find them in chemical sunscreens than mineral ones - check the "inactive ingredients" on the label - but any sunscreen whether marketed as chemical or mineral could still be using a cheap preservative base like parabens. So also avoid ingredients that end in the word paraben, such as methylparaben.
A Quick Recap - What to Look For
To sum it up, in general you want to:
- Stay away from chemical sunscreens (and words like cinnamates, benzone, and camphor).
- Instead, look for mineral sunscreens / sunblocks that use ONLY zinc oxide and/or titanium dioxide as their UV blocking agent.
- Remember to look for the words paraben and camphor in the inactive ingredient listing on any sunscreen you buy - mineral or chemical.
At Block Island Organics, you can be sure we don’t use any of these ingredients in our sunblocks.
A great website for more information and stunning photography, such as below, is the Catlin Survey. Their mission is "To scientifically record the world’s coral reefs and reveal them to all in high-resolution, 360-degree panoramic vision."
If you are interested in more about suncare, check out our series of suncare articles here.
