We used ultraviolet-ray irradiation and conditions of high temperature and humidity to study the stability of a compound of a special type of ethylene acetic acid vinyl (EVA) capsule composed of EVA/quartz and quartz/EVA/quartz, focusing on their deterioration over time. The cause of deterioration of the quartz/EVA/quartz was analyzed. It was observed that the quality of transmission of quartz/EVA/quartz increased with a short wavelength light of 250-400 nm, corresponding to the intensity of ultraviolet-rays. However, the transmissivity of EVA/quartz did not increase with a short light wavelength. Cracking and yellowing of EVA films was also seen in part of the experimental sample. (C) 2004 Elsevier B.V. All rights reserved.