Labeling regulations are now more comprehensive
In the past, the sun protection factor number (SPF) found on labels referred only to ultraviolet B (UVB) radiation, one type of skin-damaging sunlight component. Ultraviolet A (UVA) radiation also is a danger, contributing to premature aging and skin cancer risk. Current labeling requirements cover both UVB and UVA, which helps people better evaluate which products protect against all types of radiation from sun exposure.
For the sunscreen newbie, it helps to understand that SPF is a measure of the time it would take an individual to burn in the sun if they were not wearing sunscreen vs. the time it would take them to burn with sunscreen. But the scale isn’t linear, so SPF 30 is not twice the protection of SPF 15.
Screen your screen
No sunscreens offer 100% protection, but over the course of a lifetime, even a difference of 1 to 2% in a product’s ability to block rays can add up. A product with an SPF 15 blocks about 94% of ultraviolet rays, an SPF 30 blocks 97%, and an SPF 45 blocks about 98% of rays. Other consumer protections include:
Only sunscreens with an SPF of 15 or higher may be labeled “broad spectrum,” indicating that they will block both UVA and UVB rays, and can claim to reduce the risk of premature aging and skin cancer.
The SPF on non-broad spectrum sunscreens indicates sunburn protection only. These products do not protect against skin cancer and skin aging. Non-broad spectrum sunscreens with SPF 14 or lower require a warning label that the product isn’t proven to protect against skin cancer or skin aging.
Labels may indicate water resistance of up to 80 minutes, but products are unable to make claims of being waterproof or sweatproof.
Enjoy the sun safely
For consumers who prefer to reduce chemical exposure, many health experts advise sticking to physical sunscreens, which include only zinc oxide and/or titanium dioxide in the active ingredient list. However, this is not practical or affordable for many people, so keep in mind these other steps for reducing skin cancer risk:
Minimizing sun exposure when the sun's rays are the strongest (10 a.m. to 2 p.m.).
Wearing a broad-brimmed hat and covering skin with clothing, when possible, but keeping in mind that a plain white t-shirt only offers an SPF of about 8. Darker colors typically offer more protection.
Using a water-resistant sunscreen if swimming or sweating.
Reapplying sunscreen at least every twp hours, or more often according to activity level and label directions.
("Questions and Answers: FDA announces new requirements for over-the-counter (OTC) sunscreen products marketed in the U.S." U.S. Food and Drug Administration. Accessed June 16, 2011. Available at www.fda.gov/Drugs/ResourcesForYou/Consumers/BuyingUsingMedicineSafely/UnderstandingOver-the-CounterMedicines/ucm258468.htm)