Decrease (-) Restore Default Increase (+)
Print    Email
Bookmark and Share

Health Information

Health Information

Health Information

Healthwise Catholic Symptom Checker - Definition

Search Health Information    Sun Protection Factor (SPF)

Sun Protection Factor (SPF)

Sun protection factor (SPF) is a number on sunscreen labels that shows how long skin can be in the sun and maintain a low risk for sunburn. The higher the SPF number, the longer it protects a person from the sun's burning rays.

It is important to read the information on the sunscreen label about the SPF factor listed on the label and how much protection it gives the skin. The sunscreen should be applied according to the directions on the label so it is most effective in protecting the skin from the sun's ultraviolet rays.

No sunscreen gives total protection, but "broad-spectrum" sunscreens that contain ingredients such as avobenzone, benzophenones, cinnamates, salicylates, sulisobenzone, titanium dioxide, and zinc oxide usually protect from ultraviolet A and B (UVA and UVB) rays. The label of the sunscreen product will say what types of UV rays it protects the skin from.

Sweating heavily, swimming, or doing other water activities reduces the SPF because sweat or water on the skin will reduce the amount of protection the sunscreen provides. Sunscreen needs to be reapplied more frequently during these activities.

Last Revised: August 28, 2013

Author: Healthwise Staff

Medical Review: William H. Blahd, Jr., MD, FACEP - Emergency Medicine & H. Michael O'Connor, MD - Emergency Medicine

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.

© 1995-2014 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.

© 2014 St. Mary's Health System   |  3700 Washington Avenue  |  Evansville, IN 47750  |  (812) 485-4000