Sunscreen labeling has always been confusing. But things have improved, thanks to FDA guidelines, which make the labels uniform and ban misleading terms.
Why use a sunscreen?
Ultraviolet (UV) rays from the sun can wreak havoc on skin. One type, UVB, causes sunburns, while UVA penetrates deeper into the skin, where it causes wrinkling and other signs of early skin aging. Both UVA and UVB cause skin cancer. A good sunscreen helps protect against both UVA and UVB.
Here’s what you’ll see (and not see) on products:
SPF (sun protection factor): This measures the ability to screen out UVB (not UVA). But SPFs above 50 provide marginal added benefit—for comparison, SPF 30 blocks 96.7 percent of UVB; SPF 50, 98 percent, and SPF 100, 99 percent. The FDA has thus proposed limiting SPF to "50+" though this part of the regulation is not yet finalized.
Broad-spectrum: This term ensures that the sunscreen protects against both UVA and UVB. Products often claimed to be broad-spectrum before but now must pass FDA’s standardized test to carry the label. Broad-spectrum sunscreens with SPF of 15 or higher may state that, besides reducing sunburn, they decrease the risk of skin cancer and early aging when used with other sun-protective measures (such as wearing a hat and protective clothing). Higher SPF values on broad-spectrum sunscreens indicate greater protection against both UVA and UVB.
Water-resistant: This means the sunscreen is effective for a specified time—40 or 80 minutes, as listed—while you’re swimming or if you sweat a lot, after which it needs to be reapplied. If it doesn’t say water-resistant, it should be reapplied more often if you swim or sweat.
Warnings: Sunscreens that are not broad-spectrum, or are broad-spectrum but have SPFs below 15, must carry an alert that they only help prevent sunburn, not skin cancer or early skin aging.
What you won’t see anymore: “waterproof” or “sweatproof” (these are meaningless since all sunscreens eventually wash off) or “sunblock” (no sunscreen blocks all UV). Sunscreens cannot say they offer “instant protection” or protect longer than two hours without reapplying unless the company proves the claim to the FDA.
Bottom line: Use a broad-spectrum sunscreen with an SPF of at least 15. If you are very sensitive to the sun or have had skin cancer, use an SPF of 30 or higher. Apply it liberally at least 15 minutes before you go in the sun and reapply at least every two hours. Use water-resistant products if you plan to swim or if you sweat a lot.