More than 6 million people are treated for squamous and basal cell skin cancers, and 104,000 are diagnosed with the deadliest type—melanoma—in the United States each year. Given that over 80 percent of all skin cancers are a direct result of ultraviolet (UV) radiation exposure from the sun, it makes good sense to smear on sunscreen before you spend time outdoors.
The sunscreen you choose, however, may not live up to the promises on its label. For its 2025 Guide to Sunscreens, the nonprofit Environmental Working Group (EWG) evaluated more than 2,200 SPF (sun protection factor) products and found that fewer than one-quarter (498) met the organization’s criteria for safety and effectiveness. Many of the sunscreens tested made misleading claims or used outdated formulas. Some even contained potentially harmful ingredients.
A high SPF number on the label, or a high price tag, is no assurance that the product you purchase is safe, or that it offers reliable sun protection.
Consumers left in the dark
The American Academy of Dermatology (AAD) recommends applying a broad-spectrum sunscreen that protects against ultraviolet A and B (UVA/UVB) rays, has an SPF of 30 or higher, and is water resistant. Beyond those parameters, there is little guidance on what type of sunscreen ingredients to choose.
As far as government oversight goes, the FDA regulates sunscreens like it does over-the-counter medications. Those regulations govern testing requirements for SPF levels, labeling guidelines, broad-spectrum UVA/UVB protection, and water resistance claims. However, the rules have changed little since the late 1990s, leaving consumers to largely fend for themselves.
Safest sunscreen ingredients?
Sunscreens come in two types: mineral and chemical. Mineral sunscreens contain titanium dioxide or zinc oxide, which form a barrier that blocks UV light. Chemical sunscreens contain ingredients like avobenzone, dioxybenzone, oxybenzone, octisalate, and cinoxate, some of which have questionable safety profiles and are easily absorbed through the skin.
A 2020 study in JAMA that included 48 people found that blood levels of avobenzone, oxybenzone, and four other chemical sunscreen ingredients were higher after a single application than the FDA’s threshold for requiring additional safety studies. Previous research raised questions about oxybenzone’s potential ability to disrupt hormones in the body.
Along with the active ingredient, 36 percent of the sunscreens the EWG tested contained fragrance blends, some of which are known allergens, hormone disruptors, and possibly carcinogens (cancer-causing chemicals).
Another concern is spray-on sunscreen, which can be easily breathed into the nose and mouth and is irritating to the lungs, especially for people with asthma. Some sunscreen sprays tested by the EWG contained the cancer-causing chemical benzene, a result of the manufacturing process (not an intentional ingredient). There have been several recalls of benzene-contaminated sunscreens in the last few years.
The only two ingredients that the FDA recognizes as safe are zinc oxide and titanium oxide, which are found in mineral sunscreens. The EWG’s recommended brands, like Attitude, Thinksport, and Love Sun Body, are all mineral sunscreens. Using one of these products instead of chemical sunscreens may be safer.
As for nanoparticles—tiny (billionths of a meter) versions of zinc oxide and titanium dioxide that sunscreen manufacturers sometimes use in their products to increase SPF and blend better into the skin—the jury is still out. Some research has shown that nanoparticles may have harmful effects when absorbed into the skin or breathed into the lungs. Other studies have found that the amount absorbed into the skin is very minimal. The EWG says the FDA needs to fully assess the risks of nanoparticles, but for now, it advises against using spray-on mineral sunscreens containing titanium dioxide or zinc oxide of any particle size.
Choosing a lotion, cream, or stick sunscreen rather than a spray can prevent unintentional inhalation of ingredients. The EWG also recommends fragrance-free products.
SPF: Is higher better?
The SPF number on the bottle indicates how much UVB protection the product offers (not how many minutes you can safely stay outside once you apply it, as some people mistakenly believe). UVB is the wavelength that’s mainly responsible for causing sunburn and non-melanoma skin cancer.
While it might seem like a higher number would indicate that a product offers significantly more sun protection, that’s only true up to a point. An SPF 30 sunscreen blocks 97 percent of UVB rays, but upwards from there, the difference is less than you might think. An SPF 50 sunscreen blocks about 98 percent, and an SPF 100 blocks 99 percent of UVB rays. A broad-spectrum sunscreen is the preferred type, because it also protects against UVA rays—which make up about 95 percent of our UV exposure, penetrate more deeply into the skin than UVB, and cause photoaging.
When it comes to preventing sunburn, super-high SPF products do seem to have the edge, however. In a study in the Journal of the American Academy of Dermatology in 2018, around 14 percent of the 199 participants who used an SPF 100+ product were sunburned after an average of six hours of sun exposure, compared to nearly 41 percent of those who used an SPF 50+ product. In a smaller study in 2020, 56 percent of participants who used an SPF 50+ sunscreen had more sunburn after up to five days of use, compared to 7 percent of those who used an SPF 100+ sunscreen.
Of course, how much a sunscreen actually protects against UV rays depends on the amount you apply, and many people don’t put on enough to adequately shield their skin. As long as you use a sunscreen with an SPF of 30 or higher and reapply it every two hours and after you swim or sweat, you should be well protected. Better yet, limit your time in the sun.
What about terms on sunscreen labels like “allergen free” and “reef safe” (meaning the product is less likely to harm aquatic wildlife when it ends up in water)? Don’t put much stock into either of these descriptions. Most sunscreens marketed as allergen free contain at least one known allergen that can provoke skin rashes, some research has found, and science hasn’t confirmed that reef-safe sunscreens are any better for the environment.
Sunscreen slip-ups
Try to avoid these common mistakes many people make when using sunscreen:
- Not applying enough. The protectiveness of any sunscreen hinges not only on what ingredients are in the bottle but also on how much you use and how often you apply it. The AAD advises putting on at least 1 ounce—enough to fill a shot glass. You may need even more, depending on your body size. Note also that chemical sunscreens need to be applied at least 15 minutes before going outside to have time to absorb. In contrast, mineral sunscreens are good to go as soon as you apply them.
- Forgetting spots. In addition to your face and uncovered arms, legs, back, and torso, you need to apply sunscreen to your neck, ears, and any exposed areas of your scalp. These parts of your body get burned, too. So do your lips, which need a layer of lip balm with an SPF 30 or higher.
- Not applying it often enough. Even a high SPF and water-resistant sunscreen will eventually stop protecting you. Reapply it about once every two hours, and more often if you’re swimming or sweating. As the AAD says, no sunscreen is “waterproof” or “sweatproof”—and those terms are not allowed. Rather, sunscreens can be “water-resistant,” which means they are effective for a specified time (40 or 80 minutes, as listed) while you’re swimming or if you sweat a lot.
- Spraying it on. Not only can you breathe in aerosols, but sprays don’t coat the skin evenly, so it’s easy to miss spots. They may also be harmful to the environment.
- Not using it every day. Don’t reserve sun protective products for days at the beach or pool. You’re exposed to UV rays every time you go outside, year-round, even on cloudy days (up to 80 percent of UV rays can penetrate clouds). Make sunscreen part of your daily routine.
- Believing that dark skin doesn’t need sun protection. Skin of color contains more melanin, the pigment that provides color. While melanin does offer sun protection, it’s very small—the equivalent of 1.5 to 2 SPF. It’s still essential for people of color to protect their skin from sunburn, skin aging, and skin cancer.
- Using an expired sunscreen. Pay attention to the date on the bottle. Sunscreens are only formulated to retain their original strength for about three years. After that time, these products can separate or form clumps, rendering them less effective.
BOTTOM LINE: Wearing a broad-spectrum, high-SPF sunscreen lotion (not spray), along with sun-protective clothing, sunglasses, and a wide-brimmed hat, is the best way to protect yourself against the UV rays that cause sunburn, skin cancer, and premature skin aging. However, not every sunscreen is equally safe and effective. In general, mineral sunscreen lotions are safer than chemical ones, but if you’re not sure which one to buy, use the EWG’s guide to help you choose a product. To maximize the effectiveness of your sunscreen, apply a generous amount every time you’re outdoors and reapply it about once every two hours, even on cloudy days.
