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Blocking the Blaze: The 4-1-1 on Sunscreen SPFs & UV Protection

School is out, and summer is finally here! However, with those agreeable temperatures and longer days, you may need to use more sunscreen to protect yourself from the ultraviolet radiation, or the electromagnetic energy from the sun. But what sunscreen will protect you the most?

Here, we’re sharing everything you need to know about sunscreen, sun protection factor (SPF), and ultraviolet (UV) protection.

Infographic made by Coming Home Magazine showing two hands holiding sunscreen against a blue sky background

What is Sunscreen?

Sunscreen, also known as sunblock, sun scream, or suntan lotion, is a topical solution you put on your skin to protect against sunburn and skin cancer.

It comes in many forms, including lotions, creams, sticks, gels, oils, powders, sprays, and pastes. When used as directed, sunscreen has been proven to reduce the risk of skin cancers and skin precancers by up to 50%.

It also helps minimize premature skin aging caused by the sun, like wrinkles, age spots, and sunburn.

How Does Sunscreen Block UV Rays?

Mother putting chemical sunscreen on her daughters face to protect her against skin cancer

The big deal about sunscreen is that it has active ingredients that prevent the sun’s UV radiation from reaching your skin. There are two types of sunscreens: mineral and chemical. Let’s explore the difference below:

Mineral Sunscreens

Mineral sunscreens contain the active ingredients titanium dioxide or zinc oxide and work by blocking and repelling the rays before they penetrate your skin.

Since mineral sunscreens are gentler, they’re the product of choice for babies and people with sensitive or acne-prone skin.

Chemical Sunscreens

Chemical sunscreens absorb UV rays before they can damage the skin, and contain one or more of the active ingredients:

  • Oxybenzone
  • Avobenzone
  • Octisalate
  • Octocrylene
  • Homosalate
  • Octinoxate

This type of sunscreen is ideal for daily use and for those with darker skin tones. Generally, chemical sunscreen is what people mean when they refer to sunblock—and it’s the most widely available.

What Type of Sunscreen is Best for Me?

Little boy looking at the beach with sunscreen on his back in the shape of a sun

It’s hard to figure out what sunscreen is best for you with labels each touting something unique, like waterproof, water-resistant, sport, baby, and insect repellant. Even though one sunscreen may be marketed differently, they all work similarly.

The most important factors to consider when buying sunscreen are SPF and broad-spectrum. Sunscreen goes through U.S. Food and Drug Administration (FDA) testing to determine its SPF number and broad-spectrum capabilities.

The SPF Test

The FDA has long performed an SPF test to measure a sunscreen’s ultraviolet burning (UVB) protection. UVB rays are the main cause of sunburn and can damage the DNA in skin cells directly. They’re also thought to cause most skin cancers.

After the test, a number value is assigned to the product to indicate its level of protection.

SPF refers to the amount of time it takes for UVB rays to penetrate a sunscreen and make skin go red, compared with the time it takes to do this without sunscreen.

SPF number focuses on the time it takes for UVB rays to penetrate a sunscreen and make skin go red.

Ultimately, the higher the SPF, the better UVB protection the sunscreen has. While there are multiple recommendations on the SPF you should wear and when, UVB filtration levels look like this:

  • SPF 15 sunscreens filter out about 93% of UVB rays.
  • SPF 30 sunscreens filter out about 97% of UVB rays.
  • SPF 50 sunscreens filter out about 98% of UVB rays.
  • SPF 100 sunscreens filter out about 99% of UVB rays.

Due to high filtration levels, most experts agree that SPFs 15-50 provide adequate protection for various skin types. Anything higher than SPF 50 may give you a false sense of security.

The Broad-Spectrum Test

Sunscreens can pass an optional broad-spectrum test if they provide ultraviolet aging (UVA) protection in addition to UVB protection. UVA rays can cause skin cells to age, and indirect damage to cells’ DNA.

UVA rays are mainly linked to long-term skin damage such as wrinkles, but research shows they play a role in skin cancers, too. Basically, when you see “broad-spectrum” on a label, it means the 'screen offers protection against both UVA and UVB rays.

How to Apply Sunscreen the Right Way

Little girl putting mineral sunscreen on her mothers nose to protect her skin against the sun

Try as we may, we usually don’t apply enough sunscreen or use it properly. To get the most benefit from sunscreen usage, make sure you:

  • Apply sunscreen 15-30 minutes before going outdoors to give it time to bind to your skin.
  • Rub sunscreen lotion into the skin evenly, leaving no visible streaks behind.
  • Reapply every 2 hours while outside.
  • Use one ounce of sunscreen to cover your entire body for each application. One ounce is about one shot-glass full.
  • Don’t forget the easy-to-miss spots, like the ears, back of the neck, tops of feet, and along the hairline.
  • Reapply immediately after swimming or excessive sweating.

Can You Mix Sunscreens?

Yes! You can mix sunscreens, just like mixing colors to create new ones. It can provide more protection for your skin, and you’ll feel like you’re wearing a superhero shield. But remember, just because there’s more protection doesn’t mean you can apply just one coat for the whole day.

Reapply every two hours and right after coming out from the water.  

Unleash Sun-Filled Fun

With all the essential sunscreen SPF know-how at your fingertips, you're ready to dive into an unforgettable summer under the sunny skies. Whether you're enjoying a summer grill session, splashing in the pool, or exploring new cities, your skin will stay protected.