For many of us, the scent of sunscreen is tied up with nostalgia, good and bad. A whiff can conjure up memories of quality time with family at the beach — or the pain of a severe burn from missing a spot. Sun exposure can and does damage the skin. When you’re asking how best to protect your skin from sun damage, parsing all the conflicting information out there can be a challenge.
What works best? Do certain sunscreens contain harmful chemicals? How often should we really reapply? We asked medical providers to weigh in on the sunscreen debate.
What types of sunscreen are out there?
These days, your local pharmacy’s sunscreen options seem nearly limitless. Spray or lotion, SPF 15 or 100, scented or not… the list goes on. But the active ingredients in sunscreen — components which help prevent sunburn — fall under two categories: mineral (also called physical) or chemical. Many sunscreens use both.
“The sunscreen components, we call them ‘ultraviolet filters,’” says Dr. Elma Baron, professor of dermatology at Case Western Reserve University School of Medicine. “These are the actual ingredients that filter ultraviolet light,” the wavelength of sunlight that is most damaging to the skin and is linked to skin cancer.
Mineral or physical sunscreens use mineral compounds like zinc oxide or titanium oxide to form a physical barrier against ultraviolet light. That’s why mineral sunscreens appear thicker and are harder to spread.
“Decades ago, you would see lifeguards with white noses, almost like cement,” Baron says. Luckily, chemists have improved upon the old formula, so today’s physical sunscreens are much easier to blend into your skin. But the thick or chalky feel of physical sunscreens (or the memory of them) has some consumers reaching for alternatives.
Chemical sunscreens deflect ultraviolet light by absorbing it, turning it into heat and releasing it from the skin, though your skin won’t feel warmer because of this reaction. These sunscreens are also known as organic sunscreens, though don’t confuse that with organic foods; they use carbon-based ingredients to protect against UV rays, while mineral sunscreens use inorganic ingredients.
“Mineral sunscreen is basically just ground-down rocks,” explains Lisa Quale, health educator for the University of Arizona Cancer Center’s Skin Cancer Institute. “It’s leaving a physical layer on top of your skin.”
Chemical sunscreens use a variety of active ingredients, but due to different regulatory policies, every country favors different types. In the United States, sunscreen is regulated as a medical drug, so you’ll find fewer options than in the European Union and South Korea, where sunscreen is considered a cosmetic. Some experts have pushed the US to approve more options, especially as concerns grow over the harm caused by certain ingredients on coral reefs and other marine life.
What’s the controversy over chemical sunscreen?
Both types of sunscreens are effective, and dermatologists widely agree that the harm of ultraviolet radiation is a much greater threat than any of the ingredients in sunscreen. But some consumers may be concerned about chemical sunscreens, largely due to a 2001 study that linked significant exposure of oxybenzone, an active ingredient in some products, to hormone disruption in rats.
We have no conclusive evidence that oxybenzone is dangerous for humans. A 2011 letter in the Journal of the American Medical Association noted that to reach the level of oxybenzone exposure equivalent to that which caused hormone disruption in lab rats, a person would need to apply sunscreen every day for 277 years. Since low levels of oxybenzone are present in countless everyday items, dermatologists note that avoiding it in sunscreen doesn’t make much of a difference. However, oxybenzone has been shown to contribute to coral reef bleaching, which is why Hawaii banned sunscreens that include the compound in 2018.
Other research has found that some chemical sunscreen ingredients can be absorbed into the bloodstream. In 2020, the Food and Drug Administration said it hasn’t found evidence this causes any harm to people, but they’re still studying the matter.
Which type of sunscreen is better?
Because research hasn’t found chemical sunscreens to be unsafe, the FDA and the American Academy of Dermatology endorse both types of sunscreen. So does Baron. “I hesitate to make statements like ‘Chemical sunscreens are more dangerous than physical sunscreens,’” she says. “We haven’t really done the research that is necessary to determine that, ingredient by ingredient.”
For patients concerned about putting sunscreen on young children, Baron tells them to use physical sunscreen if it makes them more comfortable. Meanwhile, mineral sunscreens are generally a better option for people with sensitive skin, or with skin conditions like rosacea or psoriasis.
Quale thinks mineral sunscreen is a safer bet in general, given that research into chemical sunscreens is still ongoing. “My general takeaway is, if you’re worried at all, stick with the mineral-based sunblock,” she says.
Whichever sunscreen you’re using, make sure to follow the written instructions on the package. Reapply regularly, generally every two hours, especially if you’re swimming or sweating. The AAD recommends using a waterproof sunscreen, SPF or 30 or higher, with broad spectrum protection, which protects against both UVA and UVB rays. And while spray sunscreens are popular for their easy application, Baron says it’s better to stick to lotions: “Sprays can evaporate more quickly, so I’m not sure it’s really staying on the skin for two hours.”
The American Academy of Pediatrics says children older than 6 months should wear sunscreen on sunny days, with an SPF between 15 and 50, and cover up with clothing and hats whenever possible. Babies younger than 6 months should stay out of the sun entirely.
Beyond sunblock
Both Quale and Baron agree that protecting your skin from the sun requires more than sunscreen. Limiting sun exposure, especially during peak sunlight hours between 10 a.m. and 4 p.m., is the most effective way to protect your skin. Shielding your skin from the sun with hats and clothing is more effective than sunscreen, which needs to be reapplied regularly and doesn’t block all UV rays.
“I wear sunscreen on my face and in makeup,” says Quayle. “But otherwise I am covered from head to toe.” She recommends wearing clothing enhanced with UPF (ultraviolet protection factor). You can also buy a laundry additive like SunGuard, which adds UV protection to your clothing and is good for several washes. As for beach trips, it’s getting easier to find stylish swimwear for kids and adults that covers more of your body, like long-sleeved rash guards, typically used by surfers.
Hats are also a great addition to your sun-blocking wardrobe. While a baseball cap will help shade your face, it doesn’t protect the back of your neck or your ears. “We see a lot of skin cancer on the ears,” Baron says. She recommends a wide-brimmed hat that provides all-around shade.
Quale, who’s been educating the public on sun safety for 15 years, shares an easy acronym to help people stay “sun-smart”: ACE.
“A is for ‘avoid too much sun’; C is for ‘cover up, with sunscreen and clothes’; and E is for ‘examine your skin and go to the dermatologist,’” she says. “That’s our major message.”