What You Need to Know About Clothing

How Does Clothing Protect Me from the Sun?

Clothing is our first line of defense against the sun’s harmful ultraviolet (UV) rays and protects us by absorbing or blocking much of this radiation. The more skin you cover, the better. A long-sleeved shirt covers more skin than a t-shirt, especially if it has a high neckline or collar that shields the back of the neck. Likewise, long pants protect more skin than shorts.

As part of a complete sun protection regimen, The Skin Cancer Foundation has always recommended covering up with clothing, including a broad-brimmed hat and UV-blocking sunglasses.

What Is UPF?

UPF stands for Ultraviolet Protection Factor. It indicates what fraction of the sun’s ultraviolet rays can penetrate the fabric. A shirt with a UPF of 50, for example, allows just 1/50th of the sun’s UV radiation to reach the skin.

Below are five examples of real fabrics magnified, all with different amounts of fiber or yarn per unit of surface area and providing different amounts of sun protection. The higher the UPF (ultraviolet protection factor), the greater the protection.

  • Mean UPF = 3
    UPF = 3

  • Mean UPF = 9
    UPF = 9

  • Mean UPF = 30
    UPF = 30

  • Mean UPF = 60
    UPF = 60

  • Mean UPF = 115
    UPF = 115

What Is the Difference Between UPF and SPF?

UPF is a rating generally used for clothing and other fabrics that protect you from the sun. It measures the amount of UVA and UVB radiation that penetrates the fabric and reaches the skin.

SPF stands for Sun Protection Factor. It is a rating for sunscreens or other cosmetic products containing sunscreen. Theoretically, the SPF number indicates how long you can stay in the sun before your skin reddens. SPF is only used to rate a sunscreen’s ability to protect against UVB rays.

How Can I Choose the Right Hat?

A wide-brimmed (3-inch or greater) hat covers places like the scalp where it is difficult to apply sunscreen or areas where people forget to apply sunscreen, including the tops of the ears and the back of the neck.

Published on June 5, 2014, Updated on May 13, 2016