Ultraviolet Protection Factor (UPF)
The UV protection factor states how long someone wearing UV protective clothing can stay out in the sun without suffering skin damage. The Ultraviolet Protection Factor (UPF) is comparable to the sun protection factor of sunscreen (SPF). In both cases, the basis for calculations is what is known as the intrinsic protection time of the skin, which can vary considerably depending on the individual skin type.
The skin of someone of skin type I with red or blond hair, blue eyes and a very fair complexion has an intrinsic protection time of approximately five to ten minutes. If they are exposed to the burning sun for longer than this without protection, they risk harmful sunburn.
When protected by a textile material with a UPF of 20, for example, this individual can extend how long they are able to stay in the sun by a factor of 20, in other words, up to a maximum of 1.5 to 3 hours (20 x 5 min = 100 min to 20 x 10 min = 200 min), without risking damage to their skin.
|UV protection||UV or SPF protection factor|
|UV protective clothing (according to UV STANDARD 801)||20 – 80|
|Tightly woven cotton clothing (according to UV STANDARD 801)||approx. 20|
|Sunscreen when applied correctly (SPF)||1 – 30|
|Lightly woven cotton clothing (according to UV STANDARD 801)||approx. 2 – 10|
|Shade under a tree||approx. 5 – 15|
|Shade under a sunshade (without special UV protection)||approx. 15|
|Shade under a sunshade (with special UV protection)||40 – 80|