Sunscreen is essential to protect against sunburns and skin cancer, but many may not be applying adequately or frequently enough.
Sunscreen can protect a person from being exposed to two different forms of ultra-violet (UV) radiation: UVA and UVB. Both forms contribute to the development of cancer and premature skin aging, but UVB is mainly responsible for sunburns. The U.S. Food and Drug Administration recommends using sunscreens that offer “Broad Spectrum” protection, which will protect against both UVA and UVB rays.
Currently available sunscreens contain a sun protection factor (SPF) range between 15 and 100. The amount of SPF relates to how much protection is offered against UVB radiation. For example, if it takes someone that has fair skin complexion 20 minutes to burn, a sunscreen with SPF 15 would theoretically allow them to stay outside 15 times longer before burning.
The American Academy of Dermatology recommends using a sunscreen with an SPF of at least 30, which will block 97 percent of UV rays. Anything above SPF 50 is likely unnecessary. There is no scientific evidence that proves using a sunscreen with an SPF higher than 50 can protect you better than a sunscreen with an SPF of 50. In fact, the U.S. Food and Drug Administration said a sunscreen containing an SPF over 50 is “inherently misleading.”
John Moore, DO, FAAFP, Aetna’s medical director for the Northeast Region, said if a person is using a sunscreen with at least an SPF of 30 and they’re applying it correctly, they should be protected. “An SPF of at least 30 or up to 50 should be used. There is no science that supports an SPF of over 50 works any better than an SPF of 50, so don’t be coerced into paying more for a product that has no science behind it.”
Also worth noting: A sunscreen with a high amount of SPF will last as long as a sunscreen with an SPF of 30 or any other lower number, according to the American Academy of Dermatology.
Most people use too little sunscreen
Whether you’re using sunscreen with SPF 30 or SPF 100, it’s imperative to correctly apply it to exposed areas of skin. If you don’t, you risk the chance that the sunscreen will offer a lower SPF than labeled because you didn’t use enough.
If a person applied 25 percent of the expected amount of an SPF 30 sunscreen, their actual sun protection factor would be less than 3.
The American Academy of Dermatology states most people apply 25 to 50 percent of the recommended amount of sunscreen. For example, if a person applied 25 percent of the expected amount of an SPF 30 sunscreen, their actual sun protection factor would be less than 3.
It takes about 15 minutes for the body to absorb sunscreen, so apply it before going outside. Most adults need at least one ounce of sunscreen to cover all exposed areas of the body. Lips can burn from the sun, applying lip balm with an SPF of 30 or more will provide protection.
Reapplying sunscreen throughout the day is equally important, Moore said. He advises reapplying every two hours and immediately after swimming or excessive amounts of sweating.
Most adults need at least one ounce of sunscreen to cover all exposed areas.
If you’re using a spray-on sunscreen, be careful to not spray it directly on your face. The FDA is currently examining the effectiveness of these types of sunscreens and if there is a safety concern if inhaled.
The sun’s UV rays can cause photokeratitis, similar to a sunburn on the eyes. Protect them with sunglasses or a hat with a wide brim.
Don’t forget about your eyes either. The sun’s UV rays can cause photokeratitis, which is similar to a sunburn on the eyes, according to the American Optometric Association. The more the eyes are exposed to UV radiation, the greater the risk of developing cataracts or macular degeneration.
Remember the sun is out all year
You will also want to pay attention to the UV Index, which estimates the risk of exposure to UV radiation. The index operates on a scale of 1 to 11+. A 0 to 2 means the risk of exposure is low; 3 to 5 means moderate risk; 6 to 7 means high risk; 8 to 10 means very high risk; and 11 or more means extreme risk, where unprotected skin and eyes can burn in minutes, according to the Environmental Protection Agency. Even on cloudy days in the fall or winter, wearing sunscreen can protect your skin.
One more reason to protect your skin: cancer
While UV rays make up only a very small portion of the sun’s rays, UV rays damage the DNA of skin cells. This makes UV rays the main cause of cancer-causing sun damage to the skin, according to the American Cancer Society.
“Skin cancer is a very common problem caused by different factors, including UV exposure,” Moore said. “Sunscreen can make a difference as long as you apply it correctly, frequently and throughout the year.”