If you've already read our The Sun and Your Skin and What Your Sunscreen Label Tells You, you already know more than the average consumer about how sun damage happens and what the FDA is doing to make safeguard you from marketing ploys when buying sunscreen. So what's left to know?
How sunscreen works to protect you from sun damage. Sunscreens protect by either blocking or absorbing harmful UV radiation before it has a chance to damage your skin cells and matrix.
Physical Protection
Some sunscreen ingredients protect your skin from UV radiation by physically blocking it providing a protective barrier between the sun and your skin. Physical blockers include zinc oxide and titanium dioxide. Of the two, zinc oxide provides the best protection because it has been shown to block nearly the entire UV-A and UV-B spectrum. Kind of makes you re-think making fun of the lifeguard's white nose, doesn't it?
Chemical Protection
Other sunscreen ingredients protect your skin by absorbing UV radiation, which stops the UV penetration at the epidermis level before it can damage deeper skin layers. Chemical sun protection is a bit tricky. Because chemicals absorb UV radiation, the sun protection stuff can itself become unstable and degrade, lessening their effectiveness. That's why it's so important to reapply sunscreens according to the instructions on the label. Reapplying sunscreens per instructions (and after you've been swimming or sweating a lot, even if the label says water resistant) ensure that you continue to have adequate sun protection.
The Protection is in the Dose
The SPF indicated on a sunscreen product, whether provided by physical blockers, chemical absorbers or both, is only achieved if the right amount of sunscreen is used. Although most sunscreen labels aren't very specific, they mean it when they say apply generously. On average, to adequately protect your body from head to toe, you need a full ounce of sunscreen that's a blob about the size of a golf ball! And that's per application.
Psychological Protection?
Perhaps one of the most valuable protections sunscreens may offer is peace of mind. When you are adequately slathered in sunscreen, experts agree that you are free to enjoy your fun in the sun without the nagging fear that skin cancer is creeping up on you. At the same time, don't get too comfortable in the sun after your initial sun protection coating. Set a timer to remind you to reapply, and don't skimp. Saving an ounce of sunscreen isn't worth the wrinkles spots or worse as reminders of sunscreen frugality. Safely enjoy the Memorial Day weekend introduction to summer!'"
