DESCRIPTION
What is UPF Testing?
Ultraviolet Protection Factor (UPF) is a weighted spectral transmission value which can quantify the amount of skin-effective UV radiation that is transmitted through materials.
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15-24 is good
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25-39 is very good
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40 or higher is excellent
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50+ is the maximum factor according to the standards.
For example, a shirt with a UPF rating of 15 means that 1/15th of the sun’s UV radiation can reach the wearer’s skin, while a shirt with a UPF rating of 50 means that only 1/50th of the sun’s UV radiation can reach the wearer’s skin. Another way to perceive this rating is a UPF of 20 (allowing 1/20th of UV through) is equivalent to blocking 95%. A UPF of 40 blocks 97.5% and a UPF of 50 blocks 98%.
TEST STANDARDS
UPF Standards:
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AATCC TM183-2010 “Transmittance or Blocking of Erythemally Weighted Ultraviolet Radiation through Fabrics”
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ASTM D6544 “UPF Standard Practice for Preparation of Textiles Prior to Ultraviolet (UV) Transmission Testing”
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ASTM D6603 “Standard Specification for Labeling of UV-Protective Textiles”
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AS NZS 4399 “Sun protective clothing—Evaluation and classification”
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BS EN 13758-1 “Textiles – Solar UV protective properties – Method of test for apparel fabrics”
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GBT18830-2009 “Textiles – Evaluation for solar ultraviolet protective properties”