UV STANDARD 801
In order to provide consumers with a reliable UPF, the particular requirements to which a sun protective textile is subjected during use must be taken into consideration.
In the case of clothing, the stretching of a fabric during wear, moisture from perspiration or water and wear during use affect the sun protection factor. Furthermore the sun protection factor is also affected during and after care of the textile. The textile material is therefore laundered as part of the test and wet during measurement and stretched in a specified manner (see picture 1).
For shading textiles, the stretching of the fabric, the weather (sun and rain) and humidity affect the sun protection factor.
As a result of these conditions, the protection time is drastically reduced (or in the worst case almost completely lost), and this must also be reflected in the UPF rating indicated to avoid putting the wearer at risk (comparison see pictures 2 and 3).
Correspondingly, the members of the International Test Association for Applied UV Protection, recommend measuring the UV protection factor according to the UV STANDARD 801 for all types of clothing and shading textiles. This is always based on the worst-case scenario for wear and use.