SPF and UPF: What's the Difference?

SPF and UPF: What's the Difference?

When it comes to sun protection, SPF and UPF are terms you'll often hear, but what do they mean?

- SPF (Sun Protection Factor): This measures how well sunscreen can protect your skin from UVB rays, which cause sunburn. Only sunscreens labeled "broad spectrum" can also protect against UVA rays, which contribute to skin aging.

- UPF (Ultraviolet Protection Factor): Think of UPF as the fabric equivalent of sunscreen. It measures how much UV radiation a fabric blocks. Unlike SPF, UPF rates the effectiveness against both UVA and UVB radiation.

For instance, a fabric with UPF 50 blocks out 98% of UV rays, while UPF 30 blocks about 97%. Aiming for a minimum of UPF 30 is essential, with UPF 50 being optimal for the best protection.

Which Clothing Offers Better Sun Protection?

Certain garments start off with a higher UPF than others. Here's what to look for:

- Color: Darker fabrics typically have a higher UPF because they absorb more UV rays. This means less UV radiation passes through to your skin.

- Tightness of Weave: The denser the fabric, the fewer openings it has, and the more UV it blocks. Tightly woven materials have a higher UPF compared to loosely woven one

- Wetness: UPF clothing is designed to remain protective when wet, but regular garments lose effectiveness. For example, a white T-shirt’s UPF drops from about 7 when dry to 3 when wet.

- Looseness: Looser-fitting clothing tends to have a higher UPF because the fabric isn’t stretched, which can create gaps and reduce protection.

- Fiber Type: Certain fibers, like polyester, scatter UV rays more effectively than others. However, fabric and yarn construction play a bigger role in UPF than the fiber type alone.

By understanding the difference between SPF and UPF and selecting the right clothing, you can enjoy the sun safely and stylishly.

Stay protected and enjoy your summer. For more insights and tips on sun protection, visit the [Skin Cancer Foundation](https://www.skincancer.org).

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