What Makes a Sunscreen Reef-Safe?

When shopping for sunscreen, you’ve probably seen terms like “reef safe” or “reef friendly.” But what do these labels actually mean? Are they regulated terms that brands must be certified to use before putting them on their products, or are they unregulated, self-promotional claims we should be wary of? And how can you check your go-to sunscreen brand?

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How Conventional Sunscreens Harm Our Ocean

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Conventional sunscreens are meant to block UVA/UVB rays, but many rely on synthetic UV filters that can harm marine ecosystems when they wash off during swimming or surfing.

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Each year, an estimated 6,000–14,000 tons of sunscreen enter coral reef areas; at least 10% of global reefs (and 40% of coastal reefs) are exposed to oxybenzone, a well-studied reef-harming filter.

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Although this pollution isn’t the main cause of coral decline (climate-driven ocean heat is), it adds to the problem.

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From Jan 2023 to Sept 2025, bleaching-level heat affected about 84% of the world’s coral reef area, the largest event on record.

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The impact is especially concentrated in high-tourism reef zones such as Hawaii, Florida/the Caribbean/Gulf of Mexico, places like Palau/Bonaire/Aruba/U.S. Virgin Islands, and the Great Barrier Reef, which has faced repeated mass bleaching since 1998.

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Because reefs support ~25% of known marine species despite covering <1% of the ocean floor, their loss cascades into major human costs: roughly 1 billion people benefit from reef services (including fisheries), healthy reefs can absorb up to 97% of wave energy (preventing large amounts of flood damage), and reef tourism economies can take steep hits after bleaching events.

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Avoid These Ingredients When Shopping for Reef-Friendly ("Reef-Safe") Sunscreen

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"Reef-safe" or "Reef-friendly” sunscreen doesn’t mean much. Because these terms aren’t regulated, brands can use them even if a sunscreen contains ingredients that may harm reefs. That’s why it’s important to check the ingredient list.

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A reef-friendly sunscreen uses only zinc oxide and/or titanium dioxide as active ingredients. If you see any other chemical ingredient, it isn’t a reef-safe option.

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Here are some ingredients to avoid:

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• Avobenzone
• Octinoxate
• Octocrylene
• Oxybenzone
• Nanoparticles
• PABA
• Parabens
• Triclosan

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Also, smaller (“nano”) mineral particles are generally considered more likely to be taken up (absorbed or ingested) by marine organisms, which is exactly why they’re a concern. So choose microsized (or labeled “non-nano”) mineral sunscreens to reduce the risk from nanoparticles (micro > nano).

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Other Simple Ways to Stay Sun Safe and Ocean Friendly

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You don’t have to rely solely on sunscreen for protection. Here are a few ocean-friendly sun hacks to pair with proper sunscreen use:

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Wear Sun-Protective Hats and Clothing

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Cover your skin with UPF-rated clothing. This reduces how much sunscreen you need to apply.

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Also read: 14 Sun Hats for Shade and Style

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Stick With Lotions, Avoid Sprays

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Use a lotion you can rub directly into your skin. Sprays can land on the sand and wash into the ocean.

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Choose Something With Good Water Resistance

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If a sunscreen stays on your body longer, it’s less likely to wash off. It’s best to follow the application instructions, including how long to wait before getting in the water.

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Avoid Peak Sun Hours

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Try to plan beach time outside the strongest UV window (often around late morning to mid-afternoon). You can also check the local UV index: when it’s high, seek shade more often, wear a hat, and UPF clothing.

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