Sunscreen: A Threat To Coral Reefs

By Stephanie


Let’s talk about reef-safe products.

Those of us who spend time in the sun often rely heavily on sunscreen to protect against UV rays. Have you stopped to think what are the ingredients? What are these products doing to our environment? What can you do to help?

Studies on coral reefs have found the chemicals found in sunscreens worn by beach goers, snorkelers and divers are having adverse effects on the health of coral reefs. In some areas thousands of visitors enter the sea day, causing dozens of chemicals to leech off skin and into our waterways.

The Federal Drug Administration (FDA) currently approves 17 sun blocks. Of these two are are physical blocks in which the suns rays are reflected and bounce away from the skin (titanium oxide and zinc oxide), the rest are chemical blocks which absorb the energy of UV radiation before it affects or damages your skin. Such chemical blocks include Avabenzon, Benzophenones, Cinnamates and Salicylates. Studies on the benzophenone Oxybenzone have shown that it is an extremely harmful chemical for coral reefs acting as an endocrine disruptor and genotoxin damaging coral DNA and altering how these organisms grow.

The UV absorbing compound also contributes to rapid and complete bleaching of hard corals, even at extremely low concentrations which in turn leads to substantial algal growth promoting phase shifts. Craig Downs, Ph.D, is one of the leading researchers on Oxybenzone at the Haereticus Environmental Laboratory in Virginia. His studies concluded that concentrations as low as 62 parts per trillion can cause vast amounts of damage... In Honolua Bay on Maui, oxybenzone levels were detected to be nearly 2,000 parts per trillion.


Notably the skin is the largest organ in the body  with many products being being absorbed into the body. Studies show that from urine samples taken from the US population 96% contained Oxybenzone, meaning the chemical  has almost almost-universal prevalence in the population. Oxybenzone enters the waterways through drainage systems and can pollute lakes, rivers and land and sea. 

Efforts to reduce pollution from oxybenzone can help protect corals from additional global anthropogenic stressors (rising sea surface temperatures, acidification, pollution). Local businesses and the service industry including eco tourism and dive shops are doing more to protect the local environment, especially those that rely on coral reefs. Notably Hawaii parts of Mexico are taking measures to ban products with oxybenzone and hopefully more places will follow suit.  Not only is it important to have reef safe sunscreen to protect our favorite environment it's important that other products such as shampoo and conditioner is reef safe.  Purchasing oxybenzone free sun screen and using reducing sunscreen usage (wearing long sleeved clothing and rash guards) is crucial. has a comprehensive list of safe sunscreens making it easier for consumers to make an informed choice on which products to buy including Stream2seaBadger, Green People and Tropical Seas.