Beauty Tips

How Does SPF Actually Work, Anyway?

And what's all this UV business?

by Kristin Booker | COMMENT

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How does sunscreen actually work? "Sunscreen works in one of two ways: it either blocks the UV radiation from entering the skin like a shield, which is known as a physical sunscreen, or it absorbs the UV radiation via a chemical reaction converting it to heat, which is known as a chemical sunscreen," Levin says.

The difference between them lies in the ingredients. "Basically, a physical sunscreen is a physical blocker, which contains one of two metals that constitute a physical blocker: zinc oxide and titanium dioxide. They act as a shield on the skin and repel ions or inorganic particles that hit on the skin, reflecting UV radiation," Levin explains. "Meanwhile, chemical sunscreens create blockers that convert UV radiation into heat on the skin's surface. Which is why we say when you apply chemical blockers, to apply it 30 minutes before you go into the sun because it takes some time to take effect as opposed to a physical blocker, which just sits on your skin like a shield."

Regardless of which type of sunscreen you choose, a broad-spectrum product is what you'll want to ensure you're protected against both types of harmful UV radiation. Which means you'll want to make sure it has the right ingredients.

Image via Imaxtree

SEE NEXT PAGE: What are the ingredients in broad-spectrum sunscreen?

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