Reef-Safe Sunscreen

By Tommy Nee

Anna Gawlik/Shutterstock.com.

You’ve probably heard someone talk about reef-safe sunscreen. You may have even thought about buying some, or had a friend share theirs when you forgot your own sunscreen. But what exactly is reef-safe sunscreen, and why does it matter?

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There are two categories of sunscreen. The first category is chemical sunscreen. Sometimes you’ll also hear this class of sunscreen referred to as “conventional sunscreen.” These are your typical drugstore sunscreens and even some higher-end luxury brands. Chemical sunscreens work by using active ingredients called UV filters. These UV filters are absorbed into your skin when you apply the sunscreen, and when UV rays from the sun come in contact with your skin, a chemical reaction occurs, and the UV filters convert the UV rays to heat. This heat is released through your skin before the UV rays can do any damage to your skin cells.

The second category of sunscreen is mineral sunscreen. Sometimes you’ll hear mineral sunscreen called “physical sunscreen.” This is because mineral sunscreen sits on top of your skin, creating a physical barrier between harmful UV rays and you. The active ingredients in mineral sunscreens are non-nano zinc oxide and/or titanium dioxide. These minerals reflect the UV rays away from your skin, protecting you from sunburn. Mineral sunscreens aren’t absorbed into your skin (and bloodstream) like chemical sunscreens, especially if you opt for a non-nano formulation. Recent research suggests that mineral sunscreens with nanoparticles are safe and effective both for humans and the environment, but I’m a big fan of non-nano formulations.

Healthy coral reef (Damsea/Shutterstock.com). Unhealthy, bleached coral reef (Sarah_lewis/Shutterstock.com).

So what does this have to do with reef-safe sunscreen, and why does any of it matter to you? When you come across a mineral sunscreen, it’s generally safe to assume that it’s reef safe. Most mineral sunscreens will be advertised as reef safe unless they have some damaging inactive ingredients, which is why it’s always important to read the inactive ingredients as well as the active ingredients. The good news is that almost all manufacturers of mineral sunscreen will use inactive ingredients that are clean, or at least, on the cleaner side of things. On the other hand, chemical sunscreens are never reef safe and damage coral reefs and the marine life that depends on them. The same active ingredients in chemical sunscreen meant to protect you can accumulate in coral tissues, leading to DNA damage and bleaching, impair photosynthesis in algae, and decrease fertility and reproduction in dolphins, whales, and other fish.

Oceanservice.noaa.gov/sunscreen

The most common active ingredients in chemical sunscreen that you should avoid are oxybenzone, avobenzone, homosalate, octisalate, octocrylene, and octinoxate. Go to your medicine cabinet or beach bag right now and look at your sunscreen! Does it contain any of these harmful UV filters? If it does, chuck it in the bin and find yourself a mineral sunscreen with clean ingredients.

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Additionally, the active ingredients in chemical sunscreens are shown to disrupt hormones and be potentially carcinogenic in humans. This is why using a reef-safe sunscreen is so important. Not only does it help protect our planet and marine life, but it also helps better protect you. Some added benefits of reef-safe and mineral sunscreen include being less irritating for sensitive skin types, more nourishing for the skin (as they often include things like mango butter and jojoba oil), and no artificial fragrance.

If you’re anything like me, which I’m guessing you are since you’re a beachcomber, you love the beach and being out in nature. Something simple like switching to a reef-safe sunscreen makes a big difference for the health of our waterways and also ourselves. So let’s use products that are good for us and good for the Earth!

References: Dr. David Harvey. Piedmont Health, The Difference Between Physical and Chemical Sunscreens. Yousuf H. Mohammed, A. Holmes, I. Haridass, W. Sanchez, H. Studier, J. Grice, H. Benson, M. Roberts, Support for the Safe Use of Zinc Oxide Nanoparticle Sunscreens: Lack of Skin Penetration or Cellular Toxicity after Repeated Application in Volunteers. National Oceanic and Atmospheric Administration, Skincare Chemicals and Coral Reefs. Environmental Working Group, The Trouble with Ingredients in Sunscreens.

This article appeared in Beachcombing Magazine Volume 48 May/June 2025.