sun protection factor

American  

noun

1. SPF.

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sun protection factor Scientific  

1. A measure, expressed numerically, of the degree to which a preparation containing sunscreen protects the skin from ultraviolet rays. The higher the value, the greater the level of protection from sun damage to the skin.

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Etymology

Origin of sun protection factor

First recorded in 1975–80

Example Sentences

The most prominent number on sunscreen bottles is the sun protection factor or SPF.

From BBC

Chemical sunscreen also allows for a higher SPF, or sun protection factor, which is a measure of how much UV radiation is needed to cause a sunburn on sunscreen-coated skin versus unprotected skin.

From Scientific American

Dermatologists recommend using a minimum sun protection factor of 30.

From New York Times

The recall includes all can sizes and all levels of sun protection factor, or SPF.

From Seattle Times

In a 1997 study, researchers instructed nine healthy people to apply sunscreen with a sun protection factor of at least 15 on their forearms, using the amount they would normally use.

From Washington Post