Don't Get Burned: What You Need to Know About Sunscreen
With all the sunscreen on the market, it can be overwhelming not only to choose the best sunscreen but also to apply the product correctly and lower the risk of sun damage -- including skin cancer. Here are a few things you need to know about how sunscreen works, good practices to adopt, and what's really in your sunscreen.
UVB rays are to blame for sunburn, but that doesn't mean UVA rays are less harmful. It penetrates the skin more deeply and can cause wrinkling and premature aging. Both can cause skin cancer. Dermatologists recommend using "broad spectrum" sunscreen that protects against UVA and UVB rays.
Sunscreen should be applied around 15 to 30 minutes before exposure for maximum effect. This allows the sunscreen enough time to properly bind to the skin and do its job.
Apply enough sunscreen to generously cover all exposed skin. For most adults, this is about 1 ounce -- enough to fill a shot glass.
The sun protection factor indicates how long sunscreened skin can be exposed to sunlight before burning compared with unprotected skin. For example, if your skin starts to burn after 10 minutes in the sun, SPF 30 sunscreen allows 30 times as much exposure, or five hours without burning -- but don't wait that long to reapply.
Applying sunscreen isn't a one-and-done activity. It must be reapplied at least every two hours while you're exposed to the sun. It should also be reapplied after swimming or sweating, which might be more often.
In addition to a container marked "broad spectrum," specific ingredients to scan for include PABA derivatives, salicylates, and/or cinnamates that absorb UVB; benzophenones (such as oxybenzone and sulisobenzone) that work against shorter-wavelength UVA; and avobenzone, ecamsule, titanium dioxide, or zinc oxide for the remaining UVA spectrum.
Under FDA rules, sunscreens can no longer be labeled "waterproof." Instead, the label "water resistant" should indicate if the sunscreen remains effective for 40 minutes or 80 minutes in the water. Although these sunscreens do work in the water, their effectiveness wears off quickly. Choose an 80-minute sunscreen for the best protection.
Spray sunscreen can be adequate as long as enough is applied to the skin. Unfortunately, it can be hard to get full coverage. The American Academy of Dermatology recommends spraying it into the hands, then applying to the body. Spray sunscreen can be dangerous to inhale, so take extreme caution to avoid fumes for adults as well as children.
Sun-protective clothing blocks most UV rays from passing through the garment. Clothing designed specifically for this purpose, including swimwear and everyday apparel, has an ultraviolet protection factor. Look for items with a UPF rating of 50 or higher.
Water, snow, and sand all reflect UV rays, which can not only increase overall UV exposure but may expose skin that isn't protected, such as the underside of the chin. Athletes who train outdoors, even in winter, are at increased risk of skin cancer and should apply sunscreen frequently.
The expiration date on sunscreen does matter. The American Academy of Dermatology recommends throwing out sunscreen that's past its expiration date. If there is no expiration date, write the date of purchase on the container, and consider tossing any unused sunscreen after three years.