SPF of 30 or greater
Short for “Sun Protection Factor,” the SPF tells you how well a product blocks ultraviolet B (UVB) rays, also known as the rays that cause sunburn.
An SPF of 15 screens 93% of the UVB rays and an SPF of 30 screens 97% of the UVB rays. While a sunscreen with a higher SPF can be beneficial for people with very fair complexions and those visiting a tropical or sun-intense region, even sunscreen with an extremely high SPF cannot screen out 100% of UVB rays.
Since SPF only indicates UVB protection, the American Academy of Dermatology recommends broad-spectrum sunscreen. “Broad spectrum” means the sunscreen also offers protection from ultraviolet A (UVA) rays, which are the rays that age the skin. The label may say, “broad spectrum” or “UVA and UVB protection.”
UVA protection is extremely important. UVA rays penetrate the skin more deeply than UVB rays. Exposure to UVA can lead to wrinkles and other signs of aging. Both UVA and UVB rays can cause skin cancer. Be sure to purchase a sunscreen that offers broad-spectrum protection.
All sunscreens wash, rub, or sweat off, so there really is no such thing as “waterproof” sunscreen. A sunscreen can be “water-resistant.” This means the product stays on the skin longer if it gets wet. You will need to reapply water-resistant sunscreen, too. Be sure to reapply approximately every 2 hours and after swimming, sweating, and toweling off. Each time you apply the sunscreen, be sure to apply generously.
Make sure you like the product
Dermatologists often say that the best sunscreen is the one that you will use. Whether you buy a lotion, spray, gel, wax stick, or cream really is a matter of personal preference. Just make sure that you like it.