Scientists learned about the importance of UVA after screens to block UVB came on the market, says Dr. Suzan
Obagi, an associate professor of dermatology and vice president of the American Board of Cosmetic Surgery.
People started using sunscreens in the 1970s, although the formulas had very low SPF and worked only against
UVB, not UVA. Since then skin cancer rates have gone up.

What happened, Obagi says, is that people felt safer with a sunscreen on and spent more time outside exposing
themselves to UVA — which resulted in the rising cancer rates. “I tell people the way to remember is: the B from
UVB is associated with burning, and the A from UVA is associated with aging,” she says.

 

The products evaluated by Consumer Reports for the most part protect the skin through chemicals that absorb
ultraviolet radiation and neutralize it, Obagi explains. But you also need a physical screen — such as zinc oxide
or titanium dioxide — to block UVA.

One other thing to keep in mind, Obagi says, is that the SPF ratings on sunscreens and sunblocks only refer to UVB
protection. “So, it’s entirely possible that you could get more protection from a sunscreen with a rating of 60 than one
with a rating of 80,” she says.