Why Reef-Safe Sunscreen Is the Only Type of Sunscreen You Should Buy

Updated: Jul. 28, 2023

Protecting your skin from the sun's harmful rays shouldn't come at the expense of underwater ecosystems. But what is reef-safe sunscreen, and will it actually protect marine life?

Incorporating chemical or natural sunscreens into your daily skin-care routine isn’t just essential for preventing damage, it’s also vital to decreasing the risk of melanoma and nonmelanoma skin cancers. But did you know that bottle of sunscreen in your medicine cabinet could be harming underwater ecosystems like coral reefs? Luckily for green living devotees, reef-friendly options exist. But what is reef-safe sunscreen, and how are common skin-care ingredients threatening marine life?

Each year, 4,000 to 6,000 tons of sunscreen washes off swimmers’ bodies into oceans, according to the National Park Service, threatening 10% of the world’s coral reefs. Research has shown that the chemicals in these sunscreens can harm coral health and reproduction, potentially contributing to the decline of coral reefs.

“Every time you get in a body of water, any topical lotion applied has the potential to wear off in the water,” says Doris Day, MD, a New York City–based dermatologist. So how can we better protect our oceanic ecosystems? Check out the best reef-safe sunscreen brands here, and read on to find out what reef-safe really means.

What is reef-safe sunscreen, exactly?

“Reef-safe is a way to categorize sunscreen that is not assumed to be harmful to the ocean’s ecosystem,” says Dr. Day. Reef-safe sunscreen is a natural or mineral-based sunscreen that only has two active ingredients: zinc oxide and titanium dioxide. Both ingredients are nontoxic to reefs and are the only active sunscreen ingredients approved by the FDA.

“Look at active ingredients, and if there is anything besides zinc and titanium, then it is not reef-safe,” says Matthew Zirwas, MD, an Ohio-based dermatologist. He points out that reef-safe sunscreen has no legal meaning or definition, which is why it’s important to be a discerning consumer and check your sunscreen ingredients. “Just because a sunscreen says reef-safe on the bottle doesn’t mean that it is safe,” he says.

Which sunscreen ingredients are reef-safe?

Commonly found in physical or mineral sunscreens, zinc oxide and titanium dioxide are two naturally occurring minerals that can block UVA and UVB radiation. Rather than absorbing into your skin, they sit on top of it to create a barrier that reflects the sun’s harmful rays—it’s why you may notice a chalky or whitish residue. These are the only two sunscreen ingredients considered reef-safe.

How do chemical sunscreens harm the oceans?

While physical sunscreens (also known as mineral sunscreens) shield the sun’s rays by creating a physical barrier on the skin, broad spectrum chemical sunscreens use active ingredients to absorb the harmful rays before your skin can. Two ingredients often found in chemical sunscreens are oxybenzone and octinoxate. Both absorb UV rays and are part of the benzophenone family. When these ingredients wear off in the water and reach coral reefs, they can damage the coral’s genetic information, disrupting its reproduction and growth cycles and leading to bleaching, according to a study published in the Archives of Environmental Contamination and Toxicology.

Algae gives coral its vibrant color, says Dr. Zirwas. “When coral gets stressed, it kicks algae out, and then the coral looks white or bleached.” But according to the World Wildlife Foundation, coral bleaching isn’t just the changing of its color, it leaves corals vulnerable to disease, affects their reproduction and growth and leads to their death. A decline in the health of corals is devastating for fish species that rely on them for food, habitat and shelter from predators.

So what stresses coral out? Warmer water temperatures tied to climate change can cause coral bleaching, so too can pollution, including chemicals in certain sunscreens.

What are the other concerns with chemical sunscreens?

Beyond the potential to harm marine life, the ingredients in chemical sunscreen can be controversial. One study published in JAMA found that six common ingredients were absorbed into the bloodstream in concentrations that surpassed the FDA threshold for safe levels. This does not mean the ingredient is unsafe and causes harm, just that it is absorbed, which is to be expected, says Dr. Zirwas.

Experts at the Environmental Working Group consider some chemical sunscreen ingredients a health risk as well, raising concerns about ingredients triggering allergies and disrupting hormones. Some studies have noted the endocrine-disrupting effects of oxybenzone, while others have shown that octinoxate can affect hormones and reproductive systems in animals.

What should not be in reef-safe sunscreens?

The following ingredients are not found in reef-safe sunscreen and should be avoided to meet reef-safe standards:

  • Oxybenzone
  • Octinoxate
  • Benzophenone-1
  • Benzophenone-8
  • 4-Methylbenzylidene camphor
  • 3-Benzylidene camphor
  • Nano-Titanium dioxide
  • Nano-Zinc oxide
  • Octocrylene

Keep in mind that nanoparticles in physical or mineral reef-friendly sunscreen products may be more toxic than larger particles, Dr. Day notes. (A nanometer is 1,000 times smaller than the thickness of a strand of hair.) Look for the words “microfine” or “micronized” before titanium dioxide and zinc oxide in sunscreens.

Is there a difference between reef-safe and reef-friendly sunscreen?

Not really. “These terms aren’t regulated, so there is no standard definition for either,” Dr. Day says. “Your best bet is making sure [the sunscreen] does not contain oxybenzone or octinoxate.”

Which states have banned chemical sunscreen?

Going on a beach vacation, weekend getaway or island-hopping cruise? Know this: A growing number of states, coastal cities and islands are taking steps to ban the reef-harming chemicals oxybenzone and octinoxate in sunscreens. These include Hawaii, the Florida Keys, Cancun, Aruba and the Virgin Islands.

Do I need reef-safe sunscreen?

While you do need to apply sunscreen daily, whether you’re using the best sunscreen sticks, powder sunscreens or face sunscreens, you don’t necessarily need something that is reef-safe. However, destinations like Hawaii, Key West and Mexico have banned the possession and sale of the chemicals found in chemical sunscreen, Dr. Day says. “If you are traveling, it’s always good to check the local protocol, as more and more governments are beginning to implement these regulations.”

If you’re not planning on being in the ocean or other naturally occurring bodies of water, any sunscreen is fine, she says.

Dr. Zirwas agrees that it depends on where you are swimming. “I use mineral sunscreen when I swim near the coral reef and chemical sunscreen if I am going to the pool and need to cover my whole body.”