Your burning questions about sun protection, answered.
If there is only one piece of beauty advice you heed, let it be the nearly religious slathering on of sunscreen. Ask any mom (or scientist). The sun’s rays, even on a gray day, not only accelerate signs of aging, they also tempt cancer. This much, you probably already know. (If not, check out our post on SPF and aging.)
But how to wade through all the info, lingo, and choices? What’s the difference between UVA and UVB? Is a physical sunscreen better than a chemical one? What about dark skin? Is it beholden to the same rules as fair complexions? No need to add worry wrinkles to the equation! Below, everything you’ve ever wanted to know about sunscreen, but were too busy flinging bikinis, flip-flops, and paperbacks into a suitcase to ask. MELISSA LANE
Q: What are UVA and UVB rays?
A: UVB (Ultraviolet B) rays are shorter wavelengths that cause sunburn and skin cancer. UVA (Ultraviolet A) rays penetrate deeper into the skin, causing some of the deadlier kinds of skin cancer as well as premature aging such as wrinkles, sunspots, and uneven skintone.
Q: What does the SPF number mean?
A: The Sun Protection Factor (SPF) specifically indicates the level of protection from UVB rays. For example: With an SPF 15, you can be in the sun roughly 15 times longer without burning than you can without it. However, different variables can affect this, so pay attention to the specific directions provided on each product label (and always check the expiration date).
Q: Is there a rule of thumb for how much to apply?
A: Most people don’t apply enough; be sure to slather it on. (But avoid rubbing it in too aggressively). Don’t forget your neck, décolleté, hands, and ears. Men should remember to apply it to their torso as melanoma is a prevalent concern in this area, whereas women should not neglect their legs. At least one ounce of sunscreen—enough to fill a shot glass, if you need a visual—is recommended to cover your body.
Q: What is broad spectrum?
A: Broad spectrum indicates protection against both UVA and UVB. This is ideally what you want to protect yourself against skin cancer and sunburn as well as early signs of aging.
Q: What is the difference between chemical and physical sunscreen?
A: A chemical sunscreen is absorbed into skin where it works by absorbing sunlight. Physical sunscreen, such as zinc oxide or titanium dioxide, sits on top of skin to form a protective barrier.
Q: Is there such a thing as waterproof?
A: Nope. The strongest term sunscreens can use is “water-resistant,” in which case they must specify the exact amount of time it will hold up when exposed to water.
Q: Do I need a different SPF for my face than my body?
A: It's fine to use the same product on your body as you do on your face, but not necessarily vice versa. If your face is sensitive, invest in a sunscreen specially formulated for your skin type. For an extra boost of free-radical defense, go for one with antioxidants.
Q: If I have dark skin, can I skip the SPF?
A: Darker-skinned people naturally produce more of a chemical called melanin, which gives the skin its color and absorbs ultraviolet rays. But that doesn’t make it immune to damage caused by the sun. As a matter of fact, skin cancer often proves to be deadlier for darker skin due to delayed detection. The bottom line is that it behooves everyone, regardless of skin color, to use sun protection.
Q: When should I apply? For that matter, when should I reapply?
A: As a basic guideline, apply 20 minutes before going out in the sun, and reapply every two hours, unless otherwise directed by the product. While this should generally maintain your coverage, take into account how quickly you burn and the SPF level you are using. If one or both numbers are low, up your frequency.