Just an innocent skinny dip in the ocean, you might think? But in truth you might be adding up to one of the biggest environmental problems scientists face nowadays – chemical sunscreen filter-caused pollution that kills the oceans and coral reefs.

Coastal travel accounts for 80% of all tourism worldwide. And this is not surprising at all – who doesn`t enjoy white sand beaches, salty air and turquoise-coloured, clear water? But at the end of the day, when the thousands of tourists are out of the water, it is left with a floating layer of oily grease and has an iridescent sheen.

After taking samples and testing for toxicity, scientists discovered that chemicals in sunscreen, generously slapped on by beachgoers, wash off in the water, and at the end of the day they stand out like a floating red flag.

Do you think it`s a coincidence that Pantone`s 2019 Colour of the Year is called Living Coral? Well, we don`t – as ocean lovers, we take note that coral is highly endangered and, as it turns out, one of the biggest threats comes directly from those who highly appreciate the beauty of reefs – beachgoers, divers and tourists.

As the number of tourists to the oceans increases, the amount of sunscreen that ends up in the marine environment also rises. About 90% of the coral reefs in the Caribbean have disappeared since 1980. And the bad guys to blame, along with higher ocean temperature and pollution, are the most common chemical sunscreen agents such as oxybenzone (benzophenone-3) and octinoxate (Ethylhexyl Methoxycinnamate).


Last year, Hawaii took action on the issue, passing a bill that will make it the first US state to ban sunscreens that are harmful to coral reefs. This ban will come into place in January 2021.

The bill focuses on two chemicals – oxybenzone and octinoxate that are found in many chemical sunscreens and have a damaging impact on the marine environment and ecosystems. High levels of these chemicals have been found in many of the tourist-beloved, world-renowned beaches. Other chemical sunscreen filters pose risks as well, which have not been properly assessed yet.


Widely studied and the most troubling UV filter – not just because it`s highly poisonous to human health and has been found in mother`s milk, but also to marine life. It is known to have a bleaching effect on coral, which can inhibit growth and possibly kill the organism. Traces of oxybenzone-powered sunscreen can promote viral infections in coral, which results in additional bleaching. Besides acting as an endocrine disruptor, oxybenzone can damage coral DNA and might lead to “reef zombies” – coral that looks healthy but is actually sterile and dead so it cannot reproduce.

A 2015 study showed that oxybenzone starts causing serious damage to coral at concentrations as low as the equivalent of one drop of water in six-and-a-half Olympic-sized swimming pools. In Hawaii, more than 10 times this amount of oxybenzone has been measured at popular swimming beaches.


It is the most widely used UVB-absorbing agent in sunscreen – also because it`s inexpensive and this allows one to keep the cost of sunscreen low. This is the other chemical UV filter that is damaging the marine ecosystem. Octinoxate has a hormone-like activity and shows thyroid and behavioural alterations in animal studies. And when washed off, according to a study conducted by Environmental Health Perspectives scientists, octinoxate caused the complete beaching of coral, even at very low concentrations.


Global warming, pollution and other human activities pose a significant threat to the marine ecosystem. By putting awareness into action, it is possible to lessen our impact on the oceans.

Using a sunscreen is a must – no compromising here, but you can and must choose a product that won`t do any harm to your or the ocean`s health. First of all, say YES to a mineral sunscreen instead of chemical UV filters. Look for a sunscreen with zinc or a combination of zinc and titanium – these naturally-occurring minerals sit on top of your skin and don`t absorb into your bloodstream. And when you swim in the ocean, these minerals just fall down to the earth from which they came.