We get this question so much that we decided to make a separate blog post about it.
The disappointing truth is not really! And honestly, when dealing with skin cancer, "not really", is a frightening answer.
While most fabrics do provide some level of protection, their UPF ratings are not as high as you may think. In fact, you can still get sunburned through a cotton T-shirt! To offer proper protection, fabric should have a rating of UPF 50+.
What does UPF mean?
The UPF stands for Ultraviolet Protection Factor which is a numerical rating to clothing.
A UPF protection clothing with rate 50 means that only 2% (1/50th) of the Ultraviolet rays can penetrate the UV blocking fabrics. The bigger the UPF rating is, the more UV protective the clothing is. (Side note: SPF refers to sun screens and UPF refers to fabric).
According to the Skin Cancer Foundation, clothing is the best way to protect your skin from harmful rays, as it doesn't wash off or require reapplication like sunscreen. But lightweight and breathable summer clothes, such as silk and white linen, only offered minimal protection from the harmful effects of the sun. A white T-shirt has a UPF of only 7! This means 1/7th of UV rays can pass through. A long-sleeve dark denim shirt has a UPF of 1700, but who wants to wear denim in the blazing sun?! Cotton, linen, and viscose frequently offer poor UV protection ranging between 5 to 25, which may be enough to avoid sun burn, but the accumulated sun exposure may lead to skin damage and ultimately skin cancer.
Here we break down what contributes to a good or bad UPF rating, so that you can make smart clothing choices.
What Enhances UPF Ratings
- Construction: Tight construction minimizes UV light that is able to pass through. Thicker fabrics also reduce UV transmission.
- Color: Generally, darker colors absorb more UV rays.
- Treatments: Fabric treatments and dyes are effective at enhancing UPF.
- Fiber type: Polyester does excellent at disrupting UV light, as does nylon
- Shiny, semi-synthetic fabrics reflect more UV radiation.
What Decreases UPF Ratings
- Fabric wetness: Wetness can cause a significant reduction in a fabric’s UPF rating.
- Fabric wear: As fabric becomes worn or fades with more uses, it also becomes less effective at blocking UV light.
- Fabric stretch: Stretched fabric can lose a significant amount of its UPF