UPF Clothing

Sun safety recommendations often focus on avoiding direct sunlight and lathering on sunscreen with a high SPF value, however, there is more that can be done to protect from harmful rays.

Doesn't all clothing block the sun?

Often, experts will suggest covering up with a swim shirt, wide brimmed hats, and more when outside, however, there's actually a lot more to clothing and its potential to shield harmful rays. Intuitively, it makes sense that the more clothing worn, or the more covered an individual's body is, the more protected they are against the sun's rays. Although this can be true, it's important to note that not all articles of clothing, nor their fabrics, are created equal when it comes to shielding harmful radiation.

As a basic example, one individual may be wearing a loosely woven, long-sleeved, bleached cotton shirt, while someone else may be wearing a tightly woven, shiny, nylon, short-sleeved shirt. Although many factors need to be considered, it may be that the person in the short-sleeved shirt has more protection, as the fabric they are wearing is tightly woven and reflective over the areas of their body that the garment covers.

Tightly woven, shiny articles of clothing made of synthetic fibers may protect against and reflect more UV rays than a loosely woven, bleached cotton or linen piece.^1,2 While more clothing often means more protection, it is important to consider the quality of the clothing worn in relation to its ability to block out the sun's radiation.

What is UPF clothing?

UPF is one way to measure the quality of an article of clothing or fabric in regards to its ability to protect against the sun. UPF stands for Ultraviolet Protection Factor, and unlike SPF, which is a measure of protection against UVB rays only, UPF takes into account a fabric or article of clothing's ability to shield both UVA and UVB rays.

UPF is a standardized metric used all over the world, and is often present on many different articles of clothing. Not every clothing item available will have a UPF label. Further, any garment without a specific UPF label or value does not mean that it is unable to protect against the sun or that you shouldn't buy it. The UPF label is just a way to make informed and confident clothing choices.

What is a good UPF value?

A garment's UPF value is a number that coincides with the fraction of UV rays it allows to pass through and hit your skin. The higher the UPF number, the better the protection. For example, a UPF of 30 allows 1/30th of the sun's UV radiation (3.3%) to pass through it. A UPF of 10 would allow 1/10th of the rays (10%) to pass through it.

UPF values of 15-20 are considered good, 25-35 is considered very good, and 40+ is considered excellent. Clothing items rated below UPF 15, such as a white cotton t-shirt rated UPF 5, are not considered protective against UV radiation. Properties that affect a fabric or garment's UPF rating include chemical treatments, dyes, fiber type, color (darker colors generally protect better), and denseness or thickness of base material.^1,2

Caring for your UPF clothing

When considering what garments are the most sun-safe, or when deciding what articles of clothing to wear or purchase, there are some tips and tricks to consider. Some of these include: