Though we’re all used to picking a sunscreen on the basis of its sun protection factor (SPF), that number refers only to UVB rays, which cause burning and skin cancer. The longer-wavelength UVA rays can wreak their own damage, though, including playing a role in premature aging and contributing to skin cancer.
The FDA is now requiring sunscreens to indicate whether they protect against UVA rays, too. If you see “Broad Spectrum SPF” on the label, that means the product has cleared the agency’s bar for protecting against both types of ultraviolet radiation. And the SPF value will indicate the degree of that protection. Read More