All sunscreen labels list a sun protection factor (SPF). SPF is a measurement of how much protection the sunscreen offers from the UVB rays that cause sunburn. A few sunscreen labels also list a "PA" ranking, which refers to the amount of protection the sunscreen offers from the UVA rays that may cause long-term skin damage. PA rankings are listed as PA+, PA++ or PA+++. The more +'s, the more protection from UVA rays. For maximum protection from both UVA and UVB rays, choose a broad-spectrum sunscreen that contains avobenzone, oxybenzone, mexoryl, zinc oxide or titanium dioxide. Apply sunscreen liberally 30 minutes before going outdoors and reapply every two hours.
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