SPF is an essential aspect of skin care. Sunscreen is key to protecting yourself – and your skin – from the sun's ultraviolet rays. Everyone should wear sunscreen, even when it's not sunny out, experts say.

The product comes in various forms − such as gels, lotions and sprays − and ingredients may vary. Perhaps the most topical debate is what's the better option: mineral sunscreen or chemical sunscreen?

Here's how to choose what's best for your skin type, according to dermatologists.

What is mineral sunscreen?

Mineral sunscreens are classified by their active ingredients, says Dr. Bruce A. Brod, a clinical professor of dermatology at the University of Pennsylvania Perelman School of Medicine. The label refers to sunscreens that contain zinc oxide, titanium dioxide or both, he adds.

"They're what we call 'inorganic sunscreens,' and they're what we call 'physical blockers,' meaning that the way they work when applied to the skin is they reflect the ultraviolet light off the skin," Brod explains.

"(Mineral sunscreens) function as a shield," says Dr. Shilpi Khetarpal, a board-certified dermatologist and associate professor of dermatology at Cleveland Clinic Lerner College of Medicine.

The ingredients in mineral sunscreens often leave a "white cast" on the skin, Khetarpal adds.

What is chemical sunscreen?

If mineral sunscreen is like a shield, chemical sunscreen is "like a sponge," explains Khetarpal.

"They absorb the ultraviolet rays, or the ultraviolet light, and then essentially break it down," she says.

"Chemical sunscreens are sunscreens that work because their chemical properties have the ability to absorb different wavelengths of ultraviolet light and prevent them from damaging the skin," Brod says.

Chemical sunscreens tend to be clear and colorless, unlike their mineral counterparts, he adds.

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Mineral sunscreen vs. chemical sunscreen

Each type of sunscreen has pros and cons, says Brod. So, it is up to the individual to decide what is right for their skin type.

Besides differing ingredients, the sunscreens' appearances may influence personal choice.

"Even with the newer formulations of the mineral sunscreens, it can be really hard to completely avoid a little bit of that whitish appearance on the skin," says Brod.

"In general, they don't tend to rub in as easily and as invisibly as the chemical sunscreens do," Khetarpal says. "Patients who have darker skin tones might not find a mineral sunscreen to be quite as cosmetically acceptable."

It is important to note, however, that if you have sensitive skin, mineral sunscreen could be better suited for you.

"Patients with really, really sensitive skin, that have more dry and irritable skin, sometimes will tolerate the mineral sunscreens better," says Khetarpal. "While allergic reactions to chemical sunscreen is relatively uncommon, we do see them sometimes."

Another key difference is how the sunscreens protect your skin.

Since chemical sunscreen absorbs into the skin, the product begins to "degrade or break down after two hours," Brod says. "They become less effective over time."

You should reapply sunscreen every two hours as a general baseline, he adds, but this might be more frequent if you are wearing chemical sunscreen.

"If you're looking from like a sun protection standpoint, the mineral ones are more effective," Khetarpal says.

Which sunscreen should I use?How to keep your skin safe – and why that SPF number matters

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