What rays does SPF block?

SPF blocks UVB rays, which are the main cause of sunburn.

Sun rays consist of two main types of ultraviolet (UV) radiation: UVA and UVB. Both UVA and UVB rays can cause skin damage, but UVB rays are the primary cause of sunburn. UVB rays are also linked to skin cancer.

SPF stands for sun protection factor, and it is a measure of how well a sunscreen protects your skin from UVB rays. The higher the SPF, the more protection you have. For example, an SPF of 30 means that the sunscreen will block 97% of UVB rays, while an SPF of 50 will block 98%.

It is important to note that SPF does not block UVA rays. UVA rays can also cause skin damage, including wrinkles and skin cancer. To protect your skin from UVA rays, you need to use a sunscreen that contains broad-spectrum protection. Broad-spectrum sunscreens will block both UVA and UVB rays.