No matter the time of year, sunscreen can be a lifesaver — it can lower your risk of skin cancer caused by overexposure to the sun on clear or cloudy days. On top of that, it can ward off premature aging of your skin.
“Even if you don’t burn easily, wearing sunscreen is still important. Sunburn is an immediate reaction, but sun damage occurs over a lifetime,” according to the John Stoddard Cancer Center in Des Moines, Iowa.
Here, we answer 12 common questions about sunscreen — one of the most convenient, least expensive ways to safeguard your skin.
1. What is sunscreen?
Sunscreen is a substance that protects your skin from the sun’s harmful rays.
Two types of sunscreen are available. Physical blockers reflect the sun’s ultraviolet (UV) rays. They contain one active ingredient, either zinc oxide or titanium dioxide. Chemical blockers contain chemicals that absorb the sun’s ultraviolet rays. In the U.S., these blockers include aminobenzoic acid, avobenzone, octisalate, octocrylene and oxybenzone.
2. What does sunscreen do?
Sunscreen helps shield your skin from the sun’s UV rays. The active ingredients in sunscreen can reduce your risk of skin cancer and can decrease skin damage, such as age spots, wrinkles and sagging.
UVA rays are most often associated with premature aging of the skin, while UVB rays are the primary cause of sunburn. Both types of rays can lead to skin cancer.
Skin cancer is the most common cancer in the world. One-fifth of Americans will develop skin cancer by the time they turn 70.
The five-year survival rate for one type of skin cancer, melanoma, is 99% if it’s detected early. However, melanoma accounts for about three-fourths of deaths from skin cancer.
3. What does SPF mean?
SPF stands for sun protection factor. It’s a worldwide system that gauges how much protection a sunscreen provides. It does this by measuring how much UVB radiation it takes for someone to get a minor sunburn with and without sunscreen being applied.
For example, if it takes 20 minutes for your unprotected skin to start turning red, using a sunscreen with an SPF of 15 theoretically prevents reddening 15 times longer, according to Dr. Ramin Fathi, a board-certified dermatologist in the Phoenix area and a spokesman for the Skin Cancer Foundation.
The SPF system does not rate the UVA protection of sunscreens.
If you’ll be spending an extended period of time outdoors, the Skin Cancer Foundation recommends applying a water-resistant, broad-spectrum sunscreen with an SPF of at least 30. The FDA’s minimum recommended SPF is 15. Keep in mind that no sunscreen can block all of the sun’s UVB rays.
4. What does “broad spectrum” mean?
A broad-spectrum sunscreen protects you from both UVA and UVB rays. All sunscreens protect against UVB rays.
5. Which sunscreen ingredients should you avoid?
For now, the answer to this question is complicated.
In 2019, the FDA proposed a revamp of federal rules governing sunscreens. One of the biggest changes would have affected which of the 16 FDA-approved active ingredients in sunscreens could be deemed “generally recognized as safe and effective,” or GRASE.
Under the FDA’s plan, two active ingredients in sunscreen, zinc oxide and titanium dioxide, would be identified as GRASE. Both are found in mineral-based sunscreens and both are widely recommended. Two other active ingredients — PABA and trolamine salicylate — would not qualify for GRASE, though. However, sunscreens sold in the U.S. don’t contain PABA or trolamine salicylate.
What about the 12 remaining FDA-approved active ingredients? The FDA said in 2019 that the GRASE standing of these ingredients, including potentially dangerous oxybenzone, would be based on a review of safety data.
However, a provision buried in the federal CARES Act of 2020 blocked the safety review. For the time being, that means all FDA-approved sunscreen ingredients are considered safe and effective.
In light of that, zinc oxide and titanium dioxide are two sunscreen ingredients that you probably don’t need to avoid.
As for the 12 active ingredients that the FDA had sought to review, oxybenzone — regularly found in nonmineral sunscreens — appears to be the most troubling. There are concerns, for instance, about the possible disruption of hormone functions and possible birth defects associated with using sunscreens with oxybenzone. As such, a number of organizations, including the Environmental Working Group, suggest avoiding sunscreens with oxybenzone. The American Academy of Pediatrics urges parents to avoid using oxybenzone-containing sunscreens on their children.
However, the Personal Care Products Council, a trade group for makers of sunscreen and an array of other products, and the American Academy of Dermatology stress that there’s no convincing scientific evidence that sunscreens with oxybenzone should be ruled out.
6. What is zinc oxide?
Zinc oxide is a white, powdery mineral found in sunscreens, baby lotions, bath soaps, foot powders, makeup, nail products and diaper-rash ointments. The Environmental Working Group says sunscreens with zinc oxide and another mineral, titanium dioxide, provide strong sun protection with few health concerns.
“The physical sunscreen ingredients zinc oxide and titanium dioxide tend to be better tolerated by people with sensitive skin,” Fathi says, “and can usually be found in sunscreens for babies and children.”
7. Is natural sunscreen superior?
Natural sunscreens — mineral-based products made with zinc oxide or titanium dioxide — are viewed by some experts as being safer than their chemical counterparts. However, some studies show sunscreens without active chemical ingredients tend to be less effective in terms of SPF and UVA protection.
The bottom line is that using a natural or chemical sunscreen is better than using no sunscreen at all.
Fathi notes that a recent study found active ingredients in chemical sunscreens are absorbed into the bloodstream. However, this absorption does not translate to toxicity, he says, and more research needs to be done to flesh out the study’s findings.
“People who may be concerned about sunscreen absorption can opt for physical [mineral] sunscreens,” Fathi says. “Out of an abundance of caution, pregnant and nursing women may want to consider using mineral sunscreens.”
8. Is sunscreen safe for everyone?
Generally, sunscreens are safe for most everybody. However, some critics warn that chemical sunscreens pose health and environmental dangers. Ultimately, deciding to apply sunscreen — and which type to apply — is a personal choice.
“Each person should make an individual decision that’s most appropriate for themselves,” says Dr. Len Lichtenfeld, deputy chief medical officer of the American Cancer Society. “But the experts who have looked at the data have concluded that the potential risk of not using sunscreen far outweighs the risks of using sunscreen.”
Fathi points out that mineral sunscreens are less likely to irritate the skin than chemical sunscreens. Therefore, people with skin that’s sensitive or skin that’s prone to acne or rosacea should avoid sunscreens containing preservatives, fragrances or alcohol, he says.
9. How often should you apply sunscreen?
The Skin Cancer Foundation suggests applying sunscreen 30 minutes before heading outside, and then reapplying it every two hours. It also should be reapplied right after swimming or working up a sweat.
10. Do you need different sunscreen for your face?
It depends on your skin type. If your face is prone to breakouts, it’s best to use a sunscreen formulated just for your face versus a standard sunscreen. Otherwise, you don’t need to apply a different sunscreen for your face. Keep in mind that many facial moisturizers contain natural or chemical ingredients designed to block harmful rays.
11. What’s the best sunscreen for babies and kids?
Sunscreen shouldn’t be applied to babies under 6 months old because of their sensitive skin. In fact, babies should be kept out of the sun altogether until they hit that age, Fathi says. Other than that, sunscreen is advised for all children.
The FDA doesn’t have special standards for sunscreens that manufacturers target toward children. The Environmental Working Group says it “has not identified any systematic differences between the types of products marketed to children and to the general population.
12. Does sunscreen expire?
The typical shelf life for sunscreen is two to three years, Fathi says.
Many sunscreens sold in the U.S. carry an expiration date on the container. The FDA cautions against using a sunscreen past its expiration date because its safety and effectiveness might have deteriorated. If your sunscreen lacks an expiration date, toss it out no more than three years after you bought it, the American Cancer Society says.
“Some sunscreens may still be effective up to six months after the expiration date,” Fathi says, “but specific ingredient formulations vary, so there’s no guarantee you’ll still get full — or any — protection.”
Sources: AIM at Melanoma Foundation, American Academy of Dermatology, American Cancer Society, ChemicalSafetyFacts.org, Consumer Reports, Environmental Working Group, Food and Drug Administration, Harvard Medical School, Houston Chronicle, Mayo Clinic, National Cancer Foundation, SheKnows, Skin Cancer Foundation, SkinCancer.net