päikesekaitsefaktori

Päikesekaitsefaktor, commonly known as SPF, is a measure of how well a sunscreen protects the skin from ultraviolet B (UVB) radiation. UVB rays are a primary cause of sunburn and play a significant role in the development of skin cancer. The SPF number indicates how much longer it takes for skin to redden after applying sunscreen compared to unprotected skin. For instance, an SPF of 30 means that it would take 30 times longer for your skin to burn than it would without any sunscreen.

It is important to understand that SPF primarily measures protection against UVB rays, while protection from ultraviolet A (UVA) rays is also crucial for preventing premature aging and skin cancer. Look for sunscreens labeled "broad spectrum" to ensure protection against both UVA and UVB radiation. The effectiveness of SPF is also dependent on proper application. This includes applying a sufficient amount of sunscreen generously to all exposed skin areas and reapplying it every two hours, or more frequently after swimming or sweating.

Higher SPF values offer more protection, but the difference in protection diminishes beyond SPF 30. For example, SPF 30 blocks approximately 97% of UVB rays, while SPF 50 blocks about 98%. While higher SPFs can be beneficial for individuals with very fair skin or those who are highly sensitive to the sun, no sunscreen can block 100% of UV radiation. Regular use of broad-spectrum sunscreen with an adequate SPF is a key component of sun safety.