Sun Protection Factor (SPF)

Sun Protection Factor (SPF) measures how well a sunscreen protects your skin from ultraviolet (UV) rays, specifically UVB rays that cause sunburn. An SPF rating indicates the theoretical time you can stay in the sun without burning compared to wearing no sunscreen at all. For example, SPF 30 means you could stay in the sun 30 times longer without burning than if you weren't wearing sunscreen. However, factors like skin type, time of day, and application amount affect its effectiveness. It's crucial to reapply sunscreen regularly, especially after swimming or sweating, to maintain protection.