HomeHealth Topics A to ZSPF, UPF & Broad-Spectrum Protection: What do they mean?
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SPF, UPF & Broad-Spectrum Protection: What do they mean?

By DuPage Medical Group Dermatology

Looking at a bottle of sunscreen can be confusing. What do all the acronyms mean? Below are some basic things you should be aware of.

SPF = Sun Protection Factor

SPF measures sunscreen protection from UVB rays which are the kind that cause sunburn and contribute to skin cancer.

  • If it takes 20 minutes for your unprotected skin to start turning red, using an SPF 15 sunscreen theoretically prevents reddening 15 times longer – about 5 hours.
  • Don’t expect any sunscreen, regardless of its SPF, to stay effective for longer than 2 hours.
  • Plus, your skin can still be damaged even without getting a sunburn

UPF = Ultraviolet Protection Factor

  • UPF measures how well a fabric blocks ultraviolet radiation.
    • A garment with a UPF of 50 only allows 1/50th of the UV radiation falling on the surface of the garment to pass through it. UPF 50+ is the highest possible rating.


  • Protects against both UVA (ultraviolet A) and UVB (ultraviolet B) sun rays.


Make sure you look for a broad-spectrum sunscreen that protects against both UVA and UVB rays and consider finding sun-protective clothing to best protect yourself in the sun this summer.

Topics and Subtopics: Skin Health

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