Type to search

The Best Reef-Safe Sunscreen

Personal Care

The Best Reef-Safe Sunscreen

Several common ingredients in sunscreens can be harmful to reefs and other sea life, which is why Hawaii and Key West, Florida, will ban the sale of sunscreens that use the UV filters oxybenzone and octinoxate as of January 1, 2021. Although no sunscreen has been proven totally safe for aquatic wildlife—wearing a rash guard or other protective clothing while you snorkel is the best choice for coral as well as for your skin—some formulas are friendlier than others. After researching the issue and testing seven sunscreens that claim to be “reef safe,” we’ve found that Thinksport SPF 50+ Sunscreen has the ingredients scientists recommend in a reef-safe sunscreen, costs less than some of the competition, is widely available, and feels nice on skin.

Our pick

Thinksport SPF 50+ Sunscreen

Thinksport SPF 50+ Sunscreen

The best reef-friendly sunscreen

This sunscreen uses ingredients that are thought to be safest for reefs. It costs less than the competition, plus it rubs in fairly easily and feels nice on skin.

$12 from Amazon
(3 ounces)

The main ingredient in Thinksport SPF 50+ Sunscreen is non-nano zinc, the most coral-friendly option available in the US, according to experts. Zinc sunscreen might conjure images of lifeguards with white noses, but this one rubs in among the clearest of those we tested, with minimal effort. Once on skin, it feels less greasy than many sunscreens, and like most mineral sunscreens—which block UV rays with zinc and titanium—its smell is more subtle compared with that of most chemical sunscreens. Like the other reef-friendly sunscreens we considered, Thinksport is a lotion, which means that it’s hard to accidentally get excess sunscreen on the sand where it will wash into the ocean, a concern when using sprays. This sunscreen typically costs $4.33 per ounce in the largest-available size; though that’s quadruple the price of our top pick for regular sunscreen, it’s less than the price of many of the other reef-friendly sunscreens we considered.

The research

  • Why you should trust us
  • Who this is for
  • How we picked and tested
  • Our pick: Thinksport SPF 50+ Sunscreen
  • Flaws but not dealbreakers
  • The competition
  • Footnotes
  • Sources

I spoke to two scientists who have researched the effects of sunscreen on sea life, Craig Downs, executive director of the nonprofit Haereticus Environmental Laboratory in Virginia, and Roberto Danovaro, PhD, a marine ecologist at Polytechnic University of Marche in Italy. I drew on research from our main sunscreen guide, for which I spoke to five dermatologists, a skin cancer educator, and a cosmetic chemist. I also looked up peer-reviewed papers on how sunscreen affects sea life.

I’ve reviewed sunscreen for Wirecutter for more than three years, and have tested dozens of sunscreens during that time. I’ve developed a refined sense of which ones feel and smell best.

If you’re headed on a reef-themed scuba or snorkel excursion, or even just to a beach in a region that’s home to coral habitats, you’ll lessen your environmental impact by using a sunscreen that skips ingredients known to be harmful to reefs in large quantities. In particular, some sunscreen ingredients can help viruses destroy corals faster, leading to bleaching, according to a 2008 paper published by Danovaro.

The reefs most vulnerable to sunscreen damage are those in highly trafficked areas without a lot of water turnover, like coastal reefs or atolls (circular reef structures left behind after an island sinks), the authors of the paper note.

Some such locations and guided tours may even require reef-safe sunscreen. As reported in The New York Times (parent company of Wirecutter), both Hawaii and Key West, Florida, voted to ban the sale of sunscreens containing two ingredients found to be harmful to coral: oxybenzone and octinoxate. The laws will take effect January 1, 2021. In the meantime, Hawaii’s state parks urge beachgoers to forgo certain ingredients, and a chain of hotels in Hawaii provides guests with complimentary reef-safe sunscreen. In Mexico, federal regulation already requires use of reef-safe sunscreen in a handful of protected areas. And the nation of Palau became the first country to ban any “reef toxic” sunscreen that contains one of 10 prohibited chemicals.

Even if you’re far from reefs, what washes off your body in the ocean (or even the shower) can make its way into the ecosystem, said Craig Downs, executive director of the nonprofit Haereticus Environmental Laboratory, though at that point the ingredients will be far, far more dilute than in the lab studies demonstrating their toxicity to reefs.

Why not just be as cautious as possible and use reef-safe sunscreen all the time? For good reasons: No sunscreen is foolproof when it comes to sea-life safety. Though good reef-safe sunscreens avoid ingredients that have been clearly demonstrated to cause damage to reefs in large doses, they may still contain trace amounts of the offending substances. Plus, scientists disagree about whether the replacement ingredients are actually safe for sea life. Beyond that, reef-safe sunscreens are pricier and harder to rub in, making them trickier to use on a daily basis to best protect your skin from UV rays that can cause painful burns or even lead to cancer. And it’s worth noting that chemicals from sunscreen aren’t the main source of worry for reefs—that would be climate change, a phenomenon bolstered by lots of other choices we make every day.

three people sat around a table with 6 bottles of sunscreen (their labels taped over so the brands are unknown)
No coral or faux cacti were harmed in our testing. Photo: Rozette Rago

There’s no label that denotes a totally reef-safe sunscreen, and it’s unclear if such a thing exists.1 “Reef safer” is probably a better way to describe the options available.

In October 2016, Downs set out to create a reef-safe sunscreen label to affix to sunscreens that passed a toxicity test in his lab. But as the applications and samples from companies rolled in, he found that even sunscreens that met the mark in theory contained impurities and unlisted ingredients that have been known to cause damage to reefs. “We’re embarrassed and horrified that no one has passed,” Downs said.

Further, though it’s clear that some sunscreen ingredients do damage to reefs, and it is wise to avoid them while near reefs, there’s no scientific consensus on the best replacements. Downs’s own list, which he calls the “HEL List” is comprised of chemicals backed by varying amounts of data, some of it quite limited. Notably, he and Danovaro strongly disagree about whether snorkelers should use zinc, a common ingredient. Part of this rift may be that they are operating under different regulations: Europe (where Danovaro is based) has more UV blockers available than the US. “Reef safe” is somewhat of a political term, defined not just by the science, but by what chemicals are approved for general use and available from manufacturers in a given region.

All of this means you can’t reach for any product that’s labeled “reef safe”—an unregulated and unclear definition—and be confident your sunscreen is harmless to the ocean environment. The best thing you can do for corals and skin alike is to cover up with protective clothing as much as possible. Danovaro said he wears a T-shirt while snorkeling.

That said, there are still a few factors to look for in sunscreen to ensure it’s more safe than the competition.

  • Minerals: The top one or two ingredients should be non-nano zinc and non-nano titanium dioxide. Particles under a hundred nanometers (in this context, considered “nano”) can be bad news for sea creatures that ingest them, like brine shrimp, and in turn the things that eat the shrimp. (Danovaro is still concerned about non-nano zinc, but in the US it’s the best option we have).
  • No oxybenzone: This common UV-stopping ingredient—a key ingredient in our main sunscreen pick—helps viruses damage coral more quickly, as Danovaro identified in his 2008 paper on reef bleaching.
  • Water resistant: All sunscreens will wash off in water, but the better they are at sticking to your skin, the less of it will wind up in the ocean with the reefs.
  • Lotion, not spray: Each time you use a spray sunscreen at the beach, some ends up on the sand, which in turn ends up in the ocean. Most mineral sunscreens are lotions, anyway.
  • No parabens: These preservatives are another virus-assisting reef-bleaching culprit. Sunscreens with parabens can be hard to identify, as parabens are often not listed in the ingredients. If a sunscreen advertises aloe or another plant component, it likely contains preservatives needed to keep that plant fresh, Downs told us, so don’t get those formulas if reef-protection is your priority.
  • Free of other ingredients that may harm coral: A small slew of chemicals aren’t great for reefs, compiled by Downs in Haereticus’s HEL List. In addition to oxybenzone and parabens, the list includes octinoxate, octocrylene, triclosan, para-aminobenzoic acid (known as PABA), camphor, and microbeads or other small bits of plastic.

Once an FDA-approved sunscreen passed the requirements for being reef safe(r), we considered the following factors:

  • SPF: The minimum SPF experts recommend to protect your skin is 30. A bit higher is better, though higher SPF offers diminishing returns in coverage.
  • Price: For sunscreen to work well, you need to reapply. A lot. Experts recommend a shot glass worth every two hours, and after you come out of the water. We sought to find a sunscreen that wasn’t a ton of money per application (with reef-safe sunscreens, each application can easily cost upwards of $6).
  • Size: Hauling one or two large bottles of sunscreen for a family day at the beach is easier than packing a bunch of small tins.

One thing to not worry about: if a sunscreen is biodegradable. This term is sometimes used interchangeably for “reef safe,” but according to Downs it’s “just a marketing word.” For example, you don’t want your zinc sunscreen particles—which are safe when they are large but harmful when they are smaller—to break down.

We selected seven sunscreens that fit our requirements (or seemed to: in a testament to how tricky it is to navigate the ingredients, one ended up containing a blocker on Downs’s HEL List). We tested each one for feel and smell, paying close attention to how difficult it was to rub in.

A bottle of thinksport sunscreen sitting upright on a wooden table.
Photo: Michael Hession

Our pick

Thinksport SPF 50+ Sunscreen

Thinksport SPF 50+ Sunscreen

The best reef-friendly sunscreen

This sunscreen uses ingredients that are thought to be safest for reefs. It costs less than the competition, plus it rubs in fairly easily and feels nice on skin.

$12 from Amazon
(3 ounces)

Thinksport SPF 50+ Sunscreen fits our requirements for a reef-safe sunscreen: It’s made with non-nano zinc, it’s water resistant, and it’s a lotion. Although it feels nice enough on skin compared with the rest of the sunscreens we considered, the main draw is its wide availability—you can find Thinksport for sale at most retailers that carry sunscreen. At $4.33 per ounce in the largest-available bottle (6 ounces), the price of this formula has gone up since we first recommended it. But it’s still less expensive than many reef-safe sunscreens we’ve considered.

Though we can’t guarantee that Thinksport is totally reef-safe, the primary ingredient is non-nano zinc, which in the US is the safest choice for sea life. It’s not shown to encourage viruses or cause damage to sea creatures who ingest it. Thinksport is also paraben-free.

Like all sunscreens we considered recommending for this guide, this sunscreen is water resistant. Wirecutter writer Kit Dillon put it to the test near his home in Hawaii (lucky him), and reported that it indeed stays on.

Because this sunscreen is a lotion, everything that leaves the bottle ends up on your skin, not blown into the sand and ocean.

Thinksport’s ingredient list is the shortest of any sunscreen we’ve tested. However, the formula contains added fragrance, giving it a strong fruity smell that did not appeal to many of our testers.

Although Thinksport sells three versions of its sunscreen, they all have the same base formula. Only the fragrances differ. The baby and kids versions are identical and have a slightly sweeter and—in our opinion—more off-putting, artificial smell than the original Thinksport.

Each Thinksport variation comes in both family-size (6-ounce) and travel-size (3-ounce) bottles. Compared with the travel-size versions, the family-size bottles cost slightly less per ounce. Since each application of sunscreen requires about a shot glass’s worth of the lotion, a single person can expect to easily use up an entire 6-ounce bottle on a daylong trip to the beach.

The Thinksport formula’s 50+ SPF rating is appealing because the minerals in physical sunscreens are not as efficient at repelling UV rays as chemical filters are at absorbing them, according to Dr. Henry Lim, a Detroit-based dermatologist and Skin Cancer Foundation spokesperson. Experts recommend looking for formulas labeled SPF 30 or more.

Like many zinc-oxide-based sunscreens, the Thinksport lotion can leave a noticeable white cast. However, as we’ve found while panel-testing dozens of sunscreens over the past few years, some people find this opacity beneficial: It helps them to see where and how much they’ve applied.

This formula feels slightly greasier than the competition—but only slightly. Not a big concern, because you’ll be in the water anyway.

Badger Broad Spectrum SPF 35 Sport felt slightly less greasy than the Thinksport. However, it has a lower SPF and costs more per ounce at the time of this writing. We tried the clear zinc version, which Badger Balm says is made up of small nanoparticles fused together to be too large for sea life to ingest.

TotLogic Natural Sunscreen SPF 30 is also slightly more matte than Thinksport. It also has a lower SPF and smells fruitier.

Alba Botanica advertises its Sport Sunscreen SPF 45 as reef-safe, and though it is free of oxybenzone‚ a major culprit, it still contains an ingredient that is thought to affect sea creatures—though it’s not clear how significant or negative those effects are.

Our testers disliked the smell of the Hello Bello Mineral Sunscreen Lotion SPF 50, finding it overly artificial and extremely sweet.

We found that Babo Botanicals Baby Mineral Sunscreen SPF 50 feels and smells good. But it’s almost double the price of Thinksport’s lotion.

Nancy Redd contributed reporting to this guide.

  1. At least in the US. Abroad, more sun-blocking ingredients are approved for use.
  1. Craig Downs, executive director of the nonprofit Haereticus Environmental Laboratory in Virginia, phone interview, May 1, 2018
  2. Roberto Danovaro PhD, marine ecologist at Polytechnic University of Marche in Italy, email interview, May 1, 2018
  3. Mehmet Ates et al, Comparative evaluation of impact of Zn and ZnO nanoparticles on brine shrimp (Artemia salina) larvae: effects of particle size and solubility on toxicity, Environmental Science: Process and Impacts, January 1, 2013
  4. Roberto Danovaro et al, Sunscreens Cause Coral Bleaching by Promoting Viral Infections, Environmental Health Perspectives, April 1, 2008
Previous Article

Leave a Comment

Your email address will not be published. Required fields are marked *