Ultraviolet protection factor

SPF is the ratio of the length of time of solar radiation exposure required for the skin to show redness (erythema) with and without protection. The term SPF or UPF (ultraviolet protection factor) has been introduced such that a garment of UPF 15 will provide the same amount of protection against solar ultraviolet radiation as a sunscreen of SPF 15. Garments with a UPF value of 20-29 offer high protection (UVR transmission 5.0-3.3%). A UPF value of 30-40 (UVR transmission 3.3-2.5%) offers very high protection and a UPF value of 40 + offers maximum protection with a UVR transmission of 2.5%. 

Fabric rinse compositions containing a UV absorber based on hydroxyaryl-l,3,5-triazine have been claimed to increase the ultraviolet protection factor (UPF) rating of treated garments to provide added protection to skin covered by the garment from UV components of sunlight [82],... 

Ultraviolet protection factor (UPF) As per legal requirements of standard products ... 

The measurement of the ultraviolet protection factor (UPF) of clothing can be performed by measuring the material s diffuse transmittance in the ultraviolet (UV) spectrum. 

Q81 An ultrablock sunscreen preparation always has a sun protection factor of 30. Sunscreen preparations protect the skin from the damage associated with ultraviolet A (UVA). 

Sunscreen preparations tend to contain substances that protect the skin against sunburn caused by ultraviolet B (UVB) rays. UVA rays are associated v/ith long-term skin damage. Sunscreen preparations contain a variety of sun protection factors but not necessarily a factor of 30. 

The frequency of application of sunscreen is guided by the SPF (sun protection factor) of the preparation. This derived value is the ratio of the time of ultraviolet exposure that causes erythema with the sunscreen to the time that causes erythema without the sunscreen. The higher the SPF, the less frequent the needed application of sunscreen. SPFs of available preparations vary from 2 to 50. 

The sun protection factor (SPF) of a given sunscreen is a measure of its effectiveness in absorbing erythrogenic ultraviolet light. It is determined by measuring the minimal erythema dose with and without the sunscreen in a group of normal people. The ratio of the minimal erythema dose with sunscreen to the minimal erythema dose without sunscreen is the SPF. Fair-skinned individuals who sunburn easily are advised to use a product with an SPF of 15 or greater. 

Diffey BL, Robson J. A new substrate to measure sunscreen protection factors throughout the ultraviolet spectrum. J Soc Cosmet Chem 1989 40 127-133. 

LDI low-dose interferon MAA melanoma-associated antigen NSAID nonsteroidalanti-inflammatory drug SPF sun protection factor TAA tumor-associated antigen TIL tumor-infiltrating lymphocyte UVA ultraviolet A UVB ultraviolet B... 

Sunscreens are a class of compounds that protect the skin from ultraviolet radiation. Wavelengths between 290nm and 400nm are particularly damaging to the skin. Sunscreens ability to absorb or reflect these damaging wavelengths are rated by their SPF or sun-protection factor. For instance a person protected with a factor-15 sunscreen will be able to stay in the sun... 

The major measurement of sunscreen photoprotection is the sun protection factor (SPF), which defines a ratio of the minimal dose of incident sunlight that will produce erythema or redness (sunburn) on skin with the sunscreen in place (protected) and the dose that evokes the same reaction on skin without the sunscreen (unprotected). The SPF provides valuable information regarding UVB protection but is useless in documenting UVA efficacy because no standard systems have been developed to measure UVA protection. Such protocols are needed because more than 85% of solar ultraviolet radiation reaching earth s surface is UVA, which penetrates more deeply into human skin than does UVB and appears to play an important role in photoaging and photocarcinogenesis. 

Wu, P.S. et al., 2014. Effects of the novel poly(methyl methacrylate) (PMMA)-encapsulated organic ultraviolet (UV) filters on the UV absorbance and in vitro sun protection factor (SPF). 

Gienerously apply sunscreen — Use about one ounce to cover all exposed skin 20 minutes before going outside. Simscreen shoidd have a Sim Protection Factor (SPF) of at least 15 and provide protection from both ultraviolet A (UVA) and ultraviolet B (UVB) rays. Reapply every two hours, even on cloudy days, and after sweating, following the apphcation directions on the bottle or tube. 

Wolf, P. et al., Topical treatment with liposomes containing T4 endonuclease V protects human skin in vivo from ultraviolet-induced upregulation of interleukin-10 and tumor necrosis factor-alpha, J. Invest. Dermatol. 114, 149-156, 2000. 

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