sun protection factor

American

noun

SPF.

sun protection factor Scientific

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.

Etymology

Origin of sun protection factor

First recorded in 1975–80

Example Sentences

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See Examples For:

sun protection factor

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

From BBC ● Jun. 30, 2025

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 ● Sep. 6, 2023

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

From Seattle Times ● Jul. 14, 2021

By way of comparison to suntan lotion, the umbrella will provide a sun protection factor of 1.2 million.

From New York Times ● Jun. 2, 2010

But pay attention to the sun protection factor, or spf, rating on the label.

From Time Magazine Archive

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023