A woman snorkeling in the ocean with a sea turtle

The effect that sunscreen may have on coral reefs and other marine life has become a major concern in recent years. Some coastal cities and the state of Hawaii have moved to ban the sale of sunscreen with certain ingredients. And sunscreen makers now label some products “reef safe” if they don’t contain oxybenzone and octinoxate, two chemicals suspected of harming coral.

But new research published in the journal Environmental Science & Technology suggests that other ingredients in sunscreens labeled reef-safe may be problematic, too.

The new study, out today, found that some ingredients in titanium-dioxide-containing sunscreens could wash off bathers and accumulate in seawater, raising more concerns about the safety of sunscreens for reefs and oceans.

This new study didn’t measure the safety of sunscreen for people, and health experts continue to say it's important for beachgoers to use it.

“It’s clear from the science that using sunscreen helps to protect against sunburns, skin cancer, and other harmful effects of the sun. The environmental impacts of sunscreen are less clear,” says Adewole Adamson, M.D., a dermatologist at the Dell Medical School at the University of Texas at Austin.

What the Study Found

Pollution, climate change, and other environmental factors are hurting oceans. Tourism is having an impact, too, says Araceli Rodriguez-Romero, Ph.D., a marine scientist at the University of Cantabria in Spain and the study's lead author. For example, each year the Mediterranean region receives more than 330 million tourists—many for seaside holidays—and the impact on the ecosystem of all those potential sunscreen users is largely unknown, she explains.  

More on Sun Safety

In a laboratory experiment, Rodriguez-Romero and her colleagues showed that ultraviolet light, used to simulate sun exposure, sped up how quickly dollops of a commercial titanium-dioxide mineral sunscreen released trace metals—from both UV filters like titanium and from other ingredients that are part of the sunscreen formula—into water from the Mediterranean. They estimated that on a typical summer day at a Mediterranean beach, sunscreen washing off bathers could increase the concentration of titanium in nearby waters by 20 percent and aluminum by 4 percent.

The researchers acknowledge that the study is preliminary. It didn't look at the direct effect of sunscreen deposits on reefs, oceans, or other marine life. And it’s not clear how—or whether—sporadic increases in the release of these metals would have an impact on marine life in a real-world scenario. Still, Rodriguez-Romero says, people should be aware of the possible effect. “If consumers are informed about the potential risk of sunscreens for the marine environment," she says, "they can demand of cosmetic companies sunscreen products that are more ocean-friendly.” 

Concerns About Sunscreen Safety

Mineral or physical sunscreens—those that use titanium dioxide or zinc oxide to deflect the sun’s harmful UV rays, are generally regarded as safe and haven’t drawn the same level scrutiny from the Food and Drug Administration as chemical sunscreens because they sit on top of the skin rather than penetrate it. But they might not offer the same level of sun protection as chemical products, such as those with avobenzone or oxybenzone. In Consumer Reports’ sunscreen tests, mineral sunscreens tend to perform not as well and therefore have lower ratings.

CR experts continue to recommend wearing sunscreen. But if you take other sun-protection steps, such as wearing UPF (ultraviolet protection factor) clothing and a broad-brimmed hat, you can use sunscreen only on exposed skin, meaning you’ll use less than you would if you were in a bathing suit. In addition, limit the time you spend in the sun when the rays are strongest—between 10 a.m. and 4 p.m.—and stay in the shade or under an umbrella. “Risk reduction is the name of the game,” says Adamson. So if you want to use less sunscreen for any reason, “make sure you reduce your risk of sun exposure in these other ways.” 

Sunscreens to Consider
The sunscreens below are the best-performing products in Consumer Reports' tests that don't contain titanium dioxide, oxybenzone, or octinoxate. 

Quick Take
Unlock Sunscreen Ratings
Quick Take
Unlock Sunscreen Ratings
Unlock Sunscreen Ratings
Unlock Sunscreen Ratings