The Sun Protection Factor (SPF) indicates how well a sunscreen protects against UVB rays, but it does not indicate protection against UVA rays. For example, SPF 15 sunscreens filter out 93% of UVB rays, and SPF 30 sunscreens filter out about 97%. When choosing sunscreen, go with a broad spectrum product that blocks both UVB and UVA light for the best protection. Remember to reapply often.
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