What is a major problem associated with selecting a sunscreen based solely on SPF?

Selecting a sunscreen based solely on SPF can lead to misunderstandings about its effectiveness because the SPF (Sun Protection Factor) primarily measures the level of protection against UVB rays, which are responsible for sunburn. While a higher SPF value indicates greater protection, it does not give a complete picture of the sunscreen's overall efficacy.

For instance, it does not account for UVA protection, which is associated with deeper skin damage and potential skin cancer. Therefore, consumers may incorrectly assume that higher SPF values offer extensive protection across the board, leading to inadequate sun safety practices. The lack of universally accepted standards for determining SPF can contribute to variability in how different products are formulated and marketed, making it difficult for consumers to make truly informed choices based solely on SPF values.

In summary, relying only on SPF ignores important factors such as broad-spectrum protection and the necessity of reapplication, which are critical for effective sun protection.