BALTIMORE (WJZ)—As summer approaches—choosing the right sunscreen can be overwhelming. How do you know which one is right for you?

MedStar Good Samaritan Dermatologist Dr. Chesahna Kindred has tips to protect you against the sun’s harmful rays.

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“Always make sure you pick a bottle that is broad-spectrum, SPF 30 or higher, and water/sweat resistant,” she says.

Broad-spectrum. Broad-spectrum sunscreens offer protection against both UVB and UVA rays, UVB or ultraviolet B rays, are the type of radiation that causes sunburn. UVA, or ultraviolet A rays, cause skin aging. It is equally important to protect against both, as too much exposure to either can damage the skin and cause skin cancer.

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SPF 30 or higher. SPF (Sunburn Protection Factor) is a measure of the product’s effectiveness against the sun’s UVB rays. The higher the SPF number, the better protection? Not necessarily, says Dr. Kindred. Always choose an SPF of at least 30 (blocks 97 percent of UVB), but don’t be fooled by labels higher than SPF 50 (blocks 98 percent of UVB). “No sunscreen can block 100 percent of UVB rays,” Dr. Kindred says. “Any product labeled higher than SPF 50 offers a minuscule fraction of added protection beyond 98 percent.”

Water and sweat resistant. It is important to use a water/sweat resistant sunscreen, even if you don’t plan on being in the water. Heat from the sun alone can make us sweat, causing sunscreen to rub off. Sunscreens are water/sweat resistant for 40 minutes—some offer additional protection, up to 80 minutes—at which point they need to be reapplied.

Dr. Kindred recommends using one ounce of sunscreen 15-30 minutes before going out in the sun and to reapply every two hours.

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