Ultraviolet protective testing

The early test methods for determining the ultraviolet protective effects of clothing involved exposing volunteers to ultraviolet radiation until their skin reddened (erythema) to a specific degree. Fortunately, instrumental methods of evaluation have been developed that eliminate the need for sunburned assistants. AATCC Test Method 183-20005 determines the transmittance of ultraviolet light through fabric samples. Through the use of established tables and formulas, the UPF is calculated. 

Initial accelerated tests have shown copolymers of 2H5V and 2H5P to be effective as ultraviolet stabilizers, particularly for acrylic polymers, and to protect the polymers for more than 20 years normal outdoor exposure to the environment. 

Infrared radiation is not visible to the human eye, but these lamps emit visible light of considerable intensity along with small amounts of ultraviolet light. For this reason, protective, dark green glasses were worn during all tests and EWI recommends this as a standard safety practice. 

Key CL, chemiluminescence UV, ultraviolet IR, infrared FTIR, Fourier-transform infrared spectroscopy TOLAS, tunable diode laser absorption spectroscopy IDS, indigo-5,5 -disulfon-ate ASTM, American Society for Testing and Materials ERA, US Environmental Protection Agency approved methods JIS, Japanese Industrial Standard WHO, World Health Organization selected methods n.a., not available. 

Under-glass weathering. This exposure technique places the specimen behind a glass-covered frame, protecting it from any direct rainfall. The solar transmittance properties of the glass filter out a significant amoimt of the harmful ultraviolet. This method is used to test interior materials. 

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