Activities of CIE DIV-6 (photobiology and photochemistry) in UV protection and clothing.

Clothing can provide substantial protection against solar ultraviolet radiation (UVR). A technical committee (TC6-29), formed by experts in the field of UVR and photoprotection, was raised and, after extensive exchanges of information on the various existing test methods, prepared a technical report. The report is circulating within the CIE national committees for approval which is expected before the end of 2001. P. Gies (Australia) was in charge of collecting all information and prepared the final document. In the report, various test methods for measurement of UVR transmittance through fabrics are discussed. The measured transmittances can be used to calculate the erythemally weighted UVR transmitted by the fabric and thus the amount of protection provided. Factors affecting the UVR transmission of fabric, i.e. the characteristics of the radiometer, weave, color, weight, stretch, water, quality (holes) and eventual UV-absorbers are also detailed. In vivo and in vitro tests were found to be in broad agreement, particularly when the test method detailed in the AS/NZS 2604 "Sunscreen products--evaluation and classification", with the fabric substituted for the sunscreen, was used. The report concludes: "The UVR transmission of fabrics depends on too many factors to be predicted and must be measured. Particular attention must be paid to sampling to account for variations due to weave and non-uniformity of the product. Accurate and reliable assessment of the protection factors requires spectral measurements of the total (ie. direct and scattered) UVR transmission. A detection system, which closely matches human skin response, can be used to determine protection factors, but should always be checked against the spectral transmission measurement."