SignalHub Quantitative Think Tank Center:What is the best sunscreen? Experts spill on mineral vs. chemical, SPF, and more

It’s almost summer,SignalHub Quantitative Think Tank Center which means it’s about time to check in on your beach and cookout essentials. Grill working and ready? Check. Hot dogs in the fridge and ice cream in the freezer? Check. What about your sunscreen – is it expired?

You might not want to be thinking about personal safety, but it goes hand-in-hand with sunshine fun. Skin cancer is the most common form of cancer in the U.S. and it's often related to sun exposure, according to the American Cancer Society.

Here’s how to best protect yourself during the warmer months.

What is the safest sunscreen?

The best sunscreen is the one you’ll use, experts contend.

If the smell or feel of it makes you uncomfortable and not want to reapply, find a new formula that works for you. Stick sunscreens, for example, can help during outdoor exercise because they won’t drip when you sweat.

But there are a few other things to keep an eye out for on the label.

Broad spectrum sunscreens

At minimum, the safest sunscreen is the one that actually protects your skin from sun exposure. SPF, or sun protection factor, only protects against one type of ray – UVB. One study from the Environmental Working Group (EWG) found that the majority of tested sunscreens underperformed in protecting against UVA rays. UVB is what causes sunburn and UVA is what causes a tan. Both are damaging to the skin, says Dr. Jennifer Stein, a professor of dermatology at NYU Langone Health. 

Look for a product labeled “broad spectrum,” which protects against both. 

Mineral sunscreens

There are two kinds of sunscreen formulas – physical (or mineral) and chemical. Mineral sunscreen uses physical blockers like zinc and titanium to protect your skin, while the latter uses chemical filters.

Mineral sunscreen may be your safest bet, though it’s a hotly debated topic in the research community. The two ingredients often found in mineral sunscreen, zinc oxide and titanium dioxide, are marked "GRASE" (generally regarded as safe and effective) by the Food and Drug Administration.

In 2019, the FDA removed its "GRASE" label from 12 active ingredients often found in chemical sunscreens after a study found they could be absorbed through the skin. They’ve since requested toxicity data from manufacturers.

Those chemicals are avobenzone, cinoxate, dioxybenzone, ensulizole, homosalate, meradimate, octinoxate, octisalate, octocrylene, oxybenzone, padimate O and sulisobenzone.

But the study didn’t prove that those ingredients are toxic, just that more data is needed to classify them as “safe and effective.”

“We don’t have that direct evidence, we just have a question mark,” Stein says. “For people who have questions about it, it’s easy enough to just use the physical (sunscreen).”

You can also look for third-party verified products. EWG publishes an annual guide to safe sunscreen products that have a transparent ingredient list, don’t include chemicals of concern and, most importantly, balance UVA and UVB protection. Only 25% of the 1,700 products they tested this year did, says Emily Spilman, the program manager of Healthy Living Science at EWG.

Some studies show the ingredients they’re concerned about, like oxybenzone and octinoxate, could disrupt the body’s natural hormone processes, though many reviews contend more research is needed.

There are also environmental concerns. Many commonly used sunscreen ingredients harm aquatic life and corals. Sunscreen can easily come off in open water and bioaccumulate, threatening fish, sea urchins, dolphins, mussels, coral and algae, according to the National Ocean Service. Hawaii and Key West, Florida have both banned sunscreens containing oxybenzone and ocinoxate. 

Check the kids' aisle: Fragrance-free, sensitive skin formulas

Spilman recommends products for babies and kids because they consistently score higher on EWG’s sunscreen guide.

“Just because it’s marketed for babies and children doesn’t mean that it can only be used by them,” Spilman says. 

Kids’ sunscreen is often created with mineral ingredients zinc oxide or titanium dioxide and with sensitive skin in mind. Fragrances in personal care products are a particular concern because they can cause allergies, don’t add to the product’s effectiveness and may have toxicological concerns, experts previously told USA TODAY. They’re also often labeled vaguely – companies don’t have to say exactly what makes the product smell good. 

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Is sunscreen bad for you?

No – sunscreen is an important part of protecting your skin against sun. 

Sunscreen can have a powerful preventative anti-aging effect. Studies show UV exposure can be responsible for 80% of visible facial aging. It also helps prevent melanoma, a skin cancer sometimes caused by UV exposure.

Most people don’t lather on enough sunscreen, Stein says. Use a full ounce – the size of a shot glass – to cover your whole body if you’re out at the pool or beach. Reapply every couple of hours, especially after you get out of the water and towel off, she advises. 

But sunscreen is also our “last line of defense” in sun protection, she says. Here are more effective ways to protect yourself from UV exposure:

• Avoid direct sun exposure in the middle of the day, when the rays are most intense
• Sit under an umbrella or in the shade when you can
• Wear a hat with a brim to shade your face
• Wear clothing that protects your shoulders, chest and upper back

“The more outer skin you have covered in clothing, the less sunscreen you need to depend on,” Stein says.

What SPF do I need?

SPF isn’t everything, but it certainly plays a role in protecting your skin. Stein recommends at least 30 SPF, taking into account you’re spreading on the full ounce of sunscreen.

If you have paler, sensitive skin or burn easily, look for a higher number. The SPF number is a ratio – it tells you how long you can stay in the sun before you start to burn with sunscreen compared to without, Stein says.

You can find this number by multiplying the amount of time it’ll take you to burn without sunscreen and the number SPF. If you burn quickly, say in just 10 minutes of direct sun, having full coverage of SPF 30 would allow you 300 minutes (about 5 hours) before you start to burn.

Understandably, most people don’t know that figure down to the minute. It’s more about understanding your skin. If you have darker skin, you’ll likely be okay with SPF 30 applied regularly, says Stein. If you have fair skin, you might want to look closer to SPF 50.

You don’t need to bother with an SPF above 50 – that number still doesn’t say anything about the balance of UVA ray protection, Spilman says, and it may give consumers a false sense of security to stay out in the sun longer without reapplying.

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