What You Need to Know About Sunscreen Ingredients

Safety concerns about chemicals in sunscreens stem from the fact that these ingredients can be absorbed through the skin. With many Americans now using these products more frequently and in larger amounts than in the past, this concern has grown.

Of the 12 ingredients the FDA is investigating, the one most often flagged as potentially worrisome is oxybenzone. This chemical is widely used in sunscreens because it effectively protects against UV rays, those that are mostly responsible for sunburn (UVB) and skin cancer (UVA). About half of the 80 sunscreen lotions, sprays, and sticks in CR’s current sunscreen ratings—including all of the recommended ones—contain oxybenzone.

There’s evidence that oxybenzone is absorbed through the skin more than was once thought, and in some studies, researchers have found detectable levels of it in human blood and breast milk. Based on animal studies, there’s concern that it could interfere with the normal function of a number of hormones, including estrogen.

In a 2001 study, researchers from the University of Zurich in Switzerland found that rats who ate food with oxybenzone mixed in had a 23 percent increase in uterine size. “There’s a difference between eating a substance and absorbing it through the skin, however,” Huber says. In fact, a study published in the Archives of Dermatology calculated that the average-sized American woman would have to apply sunscreen to 100 percent of her body every day for nearly 35 years to get the same dose of oxybenzone as the rats did. And, according to Lim (a co-author of this study), there have been no studies that have shown any harmful effects in humans, despite the evidence of absorption.

Still, a paper published today in the journal Reproductive Toxicology suggests that pregnant women who use sunscreen with oxybenzone daily might absorb enough of the chemical to increase the risk of a birth defect called Hirschsprug’s disease. Children with this condition are missing nerves in the lower colon or rectum, which prevents stool from moving through the bowel normally. The report’s findings don’t prove that oxybenzone exposure causes the condition, but it’s another piece of information that underscores the need for more research on oxybenzone and other sunscreen ingredients.

The American Academy of Pediatrics (AAP) advises parents to avoid using sunscreens with oxybenzone on children, if possible. “Studies in laboratory animals and other laboratory studies show that this chemical can mimic the actions of hormones that naturally occur in the human body. This is called endocrine disruption,” says Sophie J. Balk, M.D., an attending pediatrician at the Children's Hospital at Montefiore in the Bronx, New York, and a member of the AAP Council on Environmental Health. “As pediatricians, we are concerned about the effects of chemicals on fetuses, infants, and children because their endocrine systems and other organ systems are rapidly growing and developing. There's no research to prove adverse effects of oxybenzone on children, but there is concern.”

She notes that while a majority of the studies are specific to oxybenzone, the AAP is concerned about all chemical active ingredients in personal care products.

There is also some evidence that oxybenzone may be harmful to coral reefs, and some communities have passed legislation to ban the sale of sunscreens that contain it.

The FDA says that there’s enough current evidence to conclude that titanium dioxide and zinc oxide—ingredients that are used in mineral (sometimes called “natural”) sunscreen products—don’t warrant the same health concerns as chemical sunscreen ingredients such as oxybenzone. That's because they sit on the surface of the skin and aren't absorbed. But some experts, including those at Consumer Reports, note that they also don’t necessarily protect the skin as well as sunscreens with chemical ingredients.

“The AAD has always urged consumers who are concerned about chemical sunscreens to use mineral ones,” says Lim. “But because titanium dioxide and zinc oxide work by deflecting rather than absorbing UV rays [as chemical ingredients do], they are not as efficient filters as most chemical ingredients.”

Mineral sunscreens have consistently underperformed in CR’s testing, not always testing at the claimed SPF label on the package and failing to provide adequate protection from either UVA or UVB rays. None of the 18 sunscreens in our current ratings that contain only titanium dioxide, zinc oxide, or both scored high enough to receive a recommended designation from CR. But some did better than others and could be alternatives if you're concerned (see below).

“Patients often ask me about the health risks of sunscreens,” says Joshua Zeichner, M.D., director of cosmetic and clinical research in department of dermatology at the Mount Sinai Hospital in New York City. "I’ve even had patients wonder if it’s safer to go without.”

But, says Lim,“the negative effects of sun exposure—skin cancer and premature skin aging—are very well known. And using sunscreen has been shown to decrease those risks.” That's why the FDA isn't recommending that consumers avoid any of the active ingredients (including chemical ones) currently in sunscreen, many of which have been in use in the U.S. for more than 20 years without proven claims of negative health effects.

That advice applies to pregnant women and children, too. The American College of Obstetricians and Gynecologists recommends that pregnant women use sunscreen and doesn’t have a policy on the safety of the ingredients in it. And despite its concerns about oxybenzone, the AAP stresses that using some form of sunscreen is better than not using sunscreen at all.

“We want kids to be outside playing and enjoying the outdoors, being mindful of the importance of sun protection,” Balk says. “Using sunscreen is one way to prevent sunburn. Clothing and hats can provide an important barrier against UV rays. A child wearing a swim shirt and swim shorts will need less sunscreen, since parts of the body will be covered. And timing outdoor activities before 10 a.m. and after 4 p.m. avoids peak sun.”

(According to the AAP, babies under 6 months should be kept out of the sun or covered with protective clothing, with sunscreen used only on small areas, such as the face, if protective clothing and shade aren’t available.)

Lim also advises consumers to think of sunscreen as just one part of a total sun-protection plan that also includes covering up with clothing (or a rash guard), wearing a broad-brimmed hat, and seeking the shade or staying indoors between 10 a.m. and 4 p.m. This approach will help you shield your skin and allow you skip applying sunscreen on covered body parts.

If you're particularly concerned about the possible effects of oxybenzone, there are chemical sunscreens without it. Walgreens Hydrating Lotion SPF 50 and Hawaiian Tropic Sheer Touch Ultra Radiance Lotion SPF 50 scored well in our ratings. And if you want to use a mineral sunscreen, our tests show that California Kids Super Sensitive Lotion SPF 30+, Badger Active Natural Mineral Lotion SPF 30 (Unscented), and Goddess Garden Everyday Natural Lotion SPF 30 will offer some protection, although not as much as our top-rated products.