Is Oxybenzone Safe? The Reef, Your Blood, and One Overturned Ban

In February 2019, Key West banned the sale of sunscreens containing oxybenzone. The rule was written to start on January 1, 2021.

It never started. In June 2020 the governor of Florida signed a bill stripping every city and county in the state of the power to regulate sunscreen at all, and it took effect that July, about six months before Key West’s ban would have.

So the town at the end of the Florida Keys, sitting beside the only living coral barrier reef in the continental United States, is not allowed to decide what goes in the sunscreen sold there.

That fight is a decent way into this ingredient, because it tells you the evidence was strong enough to legislate on and contested enough that the state stepped in to stop it. Worth being precise about what happened, since it usually gets described wrong: no court struck the ban down and Key West never repealed it. The legislature simply took away the city’s power to pass it, and the ban died without ever being enforced for a day.

Where the bans actually stand

Hawaii went first and Hawaii’s stuck. Act 104 passed in 2018, took effect January 1, 2021, and it’s the reason you’ll see “Act 104 compliant” on sunscreen in Honolulu. It covers oxybenzone and octinoxate.

The US Virgin Islands went further and faster, banning oxybenzone, octinoxate and octocrylene, with the rules in force from March 2020. Palau’s ban started that January and reaches ten ingredients.

Florida is the outlier, and it’s the only place on that list where the direction reversed.

Worth knowing if you’re shopping: none of this makes a chemical sunscreen illegal to own or wear. The bans are on sale and distribution. Nobody is checking your beach bag.

What it does to coral, and why it took so long to explain

The 2016 research that started the bans found oxybenzone damaging coral larvae at very low exposures, deforming them and bleaching them. Convincing, but it left a gap: nobody could say precisely why a chemical that absorbs UV would end up harming an animal by way of sunlight.

A 2022 paper in Science filled that gap, and the answer is stranger than the original claim.

Sea anemones and mushroom coral don’t just accumulate oxybenzone. They metabolize it, attaching a sugar to it, and the thing they turn it into is a powerful photo-oxidant. The animal takes a sunscreen and converts it into a chemical that does damage specifically when the sun hits it. What was protecting against UV becomes the thing that weaponizes UV.

Then the detail that matters most in a warming ocean. The algae living inside healthy coral soak up those converted chemicals and hold onto them. Animals without their algal symbionts died at higher rates. Which means already-bleached coral, the coral in the most trouble from rising sea temperatures, is the coral least able to survive this.

That’s the part I’d want people to take away. It isn’t only that oxybenzone harms reefs. It hits hardest exactly where the reef is already failing.

The part that has nothing to do with the ocean

You may be reading this from somewhere with no reef within a thousand miles. This bit still applies.

The FDA ran maximal-use trials to find out how much sunscreen ingredient ends up in the bloodstream. The agency’s threshold for wanting further safety study is 0.5 nanograms per milliliter of plasma. Oxybenzone came back at 258 ng/mL from lotion.

That’s more than 500 times the level at which the FDA says somebody should go and check.

Read that carefully, because it’s easy to overstate. A high blood level is not the same as proven harm. It’s the trigger for asking the question, and the answer isn’t in yet. What the FDA said in its 2019 proposal is that of the sixteen sunscreen filters it looked at, only two had enough data to be called generally safe and effective: zinc oxide and titanium dioxide. Twelve others, oxybenzone among them, needed more data the industry hadn’t supplied.

Oxybenzone is also an endocrine disruptor, which is the other reason it turns up in our guide to hormone disruptors in cosmetics.

So should you stop using it

Yes, and it costs you nothing to switch, which makes this an easy call rather than a hard one.

What I don’t want anyone to take from this is “sunscreen is dangerous, skip it.” That trade is terrible. Skin cancer is a real and common disease, the sun causes it, and every dermatologist telling you to wear sunscreen is right. The researchers who ran the absorption studies said the same thing: use sunscreen.

The move is to change which sunscreen, not whether. Mineral filters do the same job by sitting on your skin and reflecting light instead of soaking in, and they’re the two ingredients the FDA already considers settled. No absorption question. No reef question.

For picks that actually rub in rather than leaving you chalky, we’ve sorted the best reef-safe sunscreens. If you’re getting in the water over a reef, Stream2Sea is certified under Protect Land + Sea, which is an actual lab test rather than a claim on the front of a bottle. Raw Elements holds the same certification and survives sweat and surf better than most. For everyday use, Badger keeps the ingredient list down to something you can read in one breath.

One habit worth building: turn the bottle over. “Reef-friendly” on the front means nothing, since no agency defines it. The active ingredients panel on the back is the only part that can’t lie to you.

Frequently asked questions

Is oxybenzone banned in the United States?

Not nationally. Hawaii’s ban took effect January 1, 2021, and the US Virgin Islands has banned it along with octinoxate and octocrylene since March 2020. Key West passed a ban in 2019, but Florida’s legislature preempted all local sunscreen rules in 2020 and it never took effect. Everywhere else in the US, it’s legal to sell.

How much oxybenzone gets absorbed into your body?

More than most people expect. In FDA maximal-use testing, oxybenzone reached about 258 nanograms per milliliter of plasma from lotion, against a 0.5 ng/mL threshold the agency uses to decide whether more safety work is needed. Absorption isn’t the same as harm, but it’s why the FDA asked for data it still hasn’t received.

Does oxybenzone really kill coral?

The mechanism is now understood rather than just observed. A 2022 study in Science showed that sea anemones and coral convert oxybenzone into a compound that becomes a strong photo-oxidant in sunlight. Animals lacking their algal symbionts died at higher rates, which suggests already-bleached coral is the most vulnerable of all.

What should I use instead of oxybenzone?

A mineral sunscreen using zinc oxide, ideally non-nano. Zinc covers the full UVA and UVB range on its own, and it’s one of only two filters the FDA has called generally safe and effective. It works the moment it’s applied, with no waiting.

Related reading

The rest of this series pulls apart what’s in a sunscreen bottle: octinoxate, the other banned filter, and zinc oxide versus titanium dioxide. For vetted picks, see the best reef-safe sunscreens. To get better at reading past the front of a bottle, our greenwashing guide covers how terms like “reef-friendly” survive without meaning anything. Every brand named has a scored profile in our brand directory.

Sources: Vuckovic et al., Conversion of oxybenzone sunscreen to phototoxic glucoside conjugates by sea anemones and corals, Science, 2022. Matta et al., Effect of Sunscreen Application on Plasma Concentration of Sunscreen Active Ingredients, JAMA, 2020. State of Hawaii, Act 104, SLH 2018. Florida Phoenix, DeSantis signs bill prohibiting Florida cities from banning any sunscreens, 2020.