Reef-Friendly Sun Protection

Image from the National Park Service's page.

Forget sunscreen on a day outdoors and you pay for it with a sunburn. But the sunscreen you choose matters for more than your skin. According to the National Park Service, many chemicals in sunscreens harm coral reef ecosystems — so reading the ingredient label is worth the effort, for your health and the ocean's.

What sunscreen does to a reef

An estimated 4,000 to 6,000 tons of sunscreen wash off into the world's oceans every year. Sunscreen pollution can bleach or deform corals and slow the growth of green algae, a key part of the food web. The damage reaches corals, fish and mammals, all the way up the food chain, including at-risk species such as the Hawaiian green sea turtle, or honu.

It is not only an ocean problem. Research shows these chemicals can harm living things in general, so the lake you swim in or the stream you wade in is affected too. Choosing reef-friendly protection every time helps ecosystems well beyond reefs.

How to choose

Some states, territories and countries have begun banning sunscreens with the harmful chemicals, but they still reach store shelves, sometimes with misleading labels. Some tips:

• Read the label. Look for zinc oxide and titanium dioxide as the active ingredients — and nothing else.
• Avoid oxybenzone, octocrylene, avobenzone, benzophenone-1, benzophenone-8, OD-PABA, 4-methylbenzylidene camphor, 3-benzylidene camphor, homosalate, octinoxate, octisalate and nanoparticles.
• Rub it on; don't spray it. Many spray sunscreens contain harmful nanoparticles, which stick to sand and wash into the sea.
• Watch for greenwashing. Some makers remove a single harmful chemical and add a "reef-friendly" sticker. Check the full ingredient list.
• Cover up instead. UV-blocking clothing, hats and sunglasses protect you without sunscreen.
• Take the pledge. The National Park Service invites visitors to pledge to protect ocean parks and share the commitment.

Protect yourself and the reef: read the fine print, slather don't spray, and cover up. National Park Service graphic.

This page is part of the National Park Service's I Didn't Know That! series.

Sources

• National Park Service: "I Didn't Know That!: Reef-Friendly Sun Protection." The source's photographs of healthy and bleached brown lobe coral (Porites evermanni), credited to Keoki Stender, are not reproduced. It spells titanium dioxide "titanium dioxde" and 4-methylbenzylidene camphor "4-Methylbenzylindene camphor"; both are corrected here.