The ABCs of sunscreen and sun safety

No matter when you spend time outside or what you’re doing, it’s important to wear sunscreen. But how do you know which is best? Sunscreen labels can be confusing, which is why Consumer Reports is here to help decode them so you can protect your skin.

Scan a sunscreen bottle and your head may spin from all the different labels: “SPF,” “sport,” and “reef safe,” are among the more common terms you’ll see. But what do they all mean?

Sunscreen will protect you against UVA rays, which are responsible for skin cancer and skin aging, and UVB rays, which are responsible for sunburn and contribute to skin cancer.

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Also important is “SPF,” which stands for sun protection factor and is a measure of how well a sunscreen protects against sunburn. But what do the different numbers next to it mean? An SPF 100 does not provide twice as much protection as an SPF 50. Instead, SPF 100 blocks 99 percent of the sun’s burning UVB rays, while SPF 50 blocks 98 percent and SPF 30 blocks 97 percent.

Sunscreens labeled “water resistant” mean they remain effective for the time stated on the bottle when you’re swimming or sweating.

Now, take words like “reef safe” and “sport.” Neither is a regulated term, and the same goes for “dermatologist tested.”

Some of the terms you see on sunscreens are just for marketing purposes and may not mean what you think they do.

Remember that no matter which sunscreen you choose, what really matters is how you apply it.

With lotions, you should use about a teaspoon per body part or area not covered by clothing, and for sprays, apply enough that your skin glistens, then rub it in.

One chemical some people worry about is oxybenzone, and you might see sunscreens labeled “no oxybenzone.” CR says that many sunscreens have been reformulated to no longer contain it.