UVA protection factor (UVA PF) is a measure of how well a sunscreen protects the skin from ultraviolet A (UVA) rays. UVA rays are a type of UV radiation that can penetrate the skin more deeply than UVB rays, which are the rays that cause sunburn. UVA rays can damage the skin’s DNA and lead to skin cancer and premature aging.
UVA PF is measured on a scale of 0 to 50+. The higher the UVA PF, the more protection the sunscreen provides from UVA rays. A sunscreen with a UVA PF of 30 will block 97% of UVA rays, while a sunscreen with a UVA PF of 50+ will block 98% of UVA rays.
It is important to note that UVA PF is not the same as SPF (sun protection factor). SPF measures how well a sunscreen protects the skin from UVB rays. A sunscreen with a high SPF may not have a high UVA PF, and vice versa.
When choosing a sunscreen, it is important to look for one with a broad-spectrum SPF of 30 or higher and a UVA PF of 30 or higher. This will ensure that the sunscreen provides protection from both UVA and UVB rays.
Here is a table that shows the relationship between UVA PF and the percentage of UVA rays that are blocked:
