Updated: Jun 4
UPF stands for ultraviolet protection factor. Clothing items and textiles can be tested for how much UV is blocked by the textile. Read more...
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What is UPF?
UPF stands for ultraviolet protection factor. Clothing items and textiles can be tested for how much UV is blocked by the textile. There are specific standardized tests that are performed that indicate how much UV is blocked initially AND sustained through 40 machine wash/dry cycles. Clothing is tested before and after the 40 cycles. Why? The testing is trying to simulate normal wear and tear that a garment may experience. The other big difference is that UPF tells us how much UVA and UVB are blocked by the textile. This is helpful because both types of UV can be responsible for UV damage to our skin over time.
How is UPF tested?
I'm happy you asked. A UPF tester takes UV light and passes it through a textile. The percent of each wavelength of light that is transmitted through the garment is recorded. This allows us to determine how much light is blocked by the textile and how much makes it through. This process is completed five times using different portions of the textile in different directions to gain a more accurate reading.
Are UPF and SPF the same?
SPF stands for sun protection factor. This is an FDA-regulated claim where companies test skincare products -lotions, moisturizers, creams, and sprays- for how much UV protection is offered. More specifically, SPF tells us how much a product is protecting our skin from experiencing a sunburn from UVB exposure. It does not tell us how much UVA is being blocked or absorbed by the product.
Is this the same device used to measure SPF of skincare products?
Interestingly, the same device is also used to measure SPF of products however an accessory tray is added to make sure that the product is evenly distributed across the slide for accurate and reproducible measurements.