Nearly 3.7 million skin cancers are diagnosed in the US annually, and the vast majority of them are caused by solar UV radiation (UVR). Clothing is the single most effective form of sun protection. It is our first line of defense against the sun’s harmful ultraviolet rays. Thing to be noted here is that, not all clothing offer equal sun protection, the tightness of the weave, the weight, type of fiber, color and amount of skin covered all affect the amount of protection they provide.
Ultraviolet Protection Factor (UPF) is a rating system used for apparel. It indicates how effectively fabrics shield skin from ultraviolet (UV) rays. The higher the UPF number, the greater degree of UV protection a garment offers. UPF gauges a fabric’s effectiveness against both ultraviolet A (UVA) and UVB light. An SPF number pertains only to a sunscreen’s effectiveness against UVB rays, the sunburn-causing segment of the ultraviolet spectrum.
A fabric with a rating of 50 will allow only 1/50th of the sun’s UV rays to pass through. This means the fabric will reduce your skin’s UV radiation exposure significantly, because only 2 percent of the UV rays will get through. The easiest way to test if a fabric can protect your skin is to hold it up to the light. If you can see through it, then UV radiation can penetrate it – and your skin.
UV-protection claims for clothing were first formalized in the 1990s in Australia, where skin cancer is a widespread concern. Researchers there developed the first fabric testing procedures for UV transmission and created a UPF rating system (see chart below). Clothing manufacturers have since voluntarily adopted this system.
|UPF Range||Protection Category||Effective UV-R
|25-39||Very Good||4.1-2.6||25, 30, 35|
|40-50, 50+||Excellent||Less than 2.5||40, 45, 50, 50+|
The higher the number, the better the protection the fabric offers. Any fabric that allows less than 2% UV transmission is simply labeled UPF 50+.
- Clothes that are marketed with a sun-protective claim usually poses UPF 50+ rating.
- When selecting clothes for sun protection, consider fabrics that have been specially treated with chemical UV absorbers, known as colorless dyes. These prevent some penetration of both UVB and UVA rays.
- Fabrics such as unbleached cotton contain special pigments called lignins that act as UV absorbers.
- Opt for High-luster polyesters and thin, satiny silk on a hot sunny day as they reflect radiation.
- Sun-protective clothing may lose its effectiveness if pulled too tight or stretched out, if they become damp or wet, or if washed and worn repeatedly.
- A laundry additive, Sun Guard, contains the sunscreen Tinosorb. When added to a detergent, it increases the UPF of the clothing, and this protection lasts through 20 washings.
A long-sleeved dark denim shirt offers an estimated UPF of 1,700 – which amounts to a complete sun block.
Note: To receive The Skin Cancer Foundation’s Seal of Recommendation, sun-protective fabrics must have a minimum UPF of 30. They consider a UPF rating of 30-49 to offer very good protection, and 50+ excellent protection.