I’m not going to spend a lot of time arguing about why you need to wear sunscreen because it really is one of those things you either get or you don’t. Sun exposure causes wrinkles. Sun exposure causes skin cancer. Skin cancer kills people (and if it doesn’t kill you it can leave some unwholesome scars). So get it already! [BONUS: For those of you on the fence, a recent study has shown that daily use of sunscreen with at least an SPF of 15 (whether or not they were going outside) actually slows down aging.]
Protecting children’s skin is even more important. Damage accumulated in childhood is the major contributor to skin problems (e.g. cancer) later in life. Any child over 6 months should be wearing sunscreen when outside. Most sunscreens have not been studied in children under 6 months and they do chemically bind with the skin so they should not be used on children under 6 months. Keep those little kiddos out of the sun as much as possible.
The harmful radiation from the sun comes in two forms (UVA and UVB) and is most concentrated from 10 am to 2 pm. Cloud cover does not affect the amount of UV radiation reaching your skin but it does remove the sensation of warmth. Both forms of UV radiation cause damage but SPF (aka sun protection factor) only refers to how the sunscreen protects against UVB exposure.
Speaking of SPF, an SPF of 6 (when properly applied) will make it so it takes 6 times as long for your skin to burn (versus unprotected skin). While raising the SPF level infinitely high to give you unlimited “sunshine time” may seem like a great idea, the maximum effective time for any sunscreen is only two hours so the difference between an SPF 50 sunscreen and an SPF 75 sunscreen is negligible. Once you pass SPF 50 there is no reason to pay extra for more SPF. (Most people are fine with an SPF of 15 to 30, when properly applied. See below for more details on that.)
Are you wondering how to protect yourself from UVA? (If not, you should be—it’s nasty stuff.) The FDA has recently implemented new rules for sunscreens making it a lot easier to know if the sunscreen protects against UVA. If a sunscreen is labeled “broad spectrum” it has UVA coverage proportional to its UVB coverage.
Sunscreens take time to be effective because they have to bind to the skin so they should be applied 15 to 30 minutes before sun exposure. Zinc oxide and titanium dioxide are the only exceptions because they sit on top of the skin. ALL sunscreens should be reapplied at least every 2 hours or more often if you are sweating or swimming. (Even water resistant sunscreens wear off after 40 to 80 minutes depending on the product.)
If you have already realized you are human and likely to miss the two hour reapply mark, you may want to try a trick one of my pharmacy school professors taught me: apply a thorough coat of sunscreen 30 minutes before heading out and a second coat just before going out. This should extend your protection a little bit (I would still reapply after 3 to 4 hours).
Proper whole-body application for an adult requires at least a generous palmful of sunscreen. I have used the spray-on sunscreen and I can definitely see the attraction when it comes to getting good coverage on wiggly arms and legs. (Don’t forget to rub it in.) I do prefer a more traditional cream or stick sunscreen for faces because I worry the coverage isn’t as good when using a spray-on sunscreen sprayed into your hands and then rubbed on the face (don’t ever spray it in your face—you will get a Darwin Award.) Speaking of your face—don’t forget the shades! Good broad spectrum sunglasses are really the only way to protect your eyes and the sensitive skin around your eyes.
Now go out there and enjoy summer!